The dipole-length, dipole-velocity and dipole-acceleration absorption oscillator strengths for the 1s^22s-1s^2np （3 ≤ n ≤9） transitions of lithium-like systems from Z = 11 to 20 are calculated by using the energie...The dipole-length, dipole-velocity and dipole-acceleration absorption oscillator strengths for the 1s^22s-1s^2np （3 ≤ n ≤9） transitions of lithium-like systems from Z = 11 to 20 are calculated by using the energies and the multiconfiguration interaction wave functions obtained from a full core plus correlation method, in which relativistic and mass-polarization effects on the energy, as the first-order perturbation corrections, are included. The results of three forms are in good agreement with each other, and closely agree with the experimental data available in the literature. Based on the quantum defects obtained with quantum defect theory （QDT）, the discrete oscillator strengths for the transitions from the ground state to highly excited states 1s^2np （n ≥ 10） and oscillator strength densities corresponding to the bound-free transitions are obtained for these ions.展开更多
Enthalpy changes of the reactions involved in our previous papers have been re-examined at the G2(MP2) and G2 levels. The G2(MP2) and G2 energies of Ar, Ar+,ArAr+, ArCl+, ArF+, ArH+, ArHe+, ArNe+, ArO+, ArS+, H2+, He,...Enthalpy changes of the reactions involved in our previous papers have been re-examined at the G2(MP2) and G2 levels. The G2(MP2) and G2 energies of Ar, Ar+,ArAr+, ArCl+, ArF+, ArH+, ArHe+, ArNe+, ArO+, ArS+, H2+, He, HeCl+, HeF+, HeO+,HeS+, Ne, NeCl+, NeF+, NeO+ and NeS+ have been calculated. The G2(MP2) and G2 results for all of the interested reactions have also been compared with those of the previous MP2/6-31G** and MP4/6-311G (2df, 2pd) calculations. All of the G2(MP2) and G2 reaction enthalpies are improved from the MP2 and MP4 level of calculations when compared with the experimental data for the four categories of reactions as (1) iso-electronic, isogyric; (2) valence isoelectronic, isogyric; (3) isogyric and (4)non-isogyric reactions with the average absolute deviations of 5.10, 4.60, 7.70 and 9.20 for G2(MP2) and 4.18, 5.19, 6.78 and 6.49kJ·mol-1 for G2, respectively. The individural deviation for almost all of the reactions involved in this work is not more than±13kJ·mol-1 for G2(MP2) and ±8.4kJ·mol-1 for G2. In this paper, an additional number of reactions examined at the G2(MP2) and G2 levels as well as at the MP2/6-31G** and MP4/6-311G (2df, 2pd) levels of calculations have also been reported. The MP2, MP4, G2(MP2) and G2 total energies for the interested chemical species have been calculated if these energies have not been reported in literatures. All of the reaction energies at different levels have been compared with the experimental data in a nummber of reactions devided into the above four categories. The average absolute deviations are 25.9, 36.0, 29.2 and 40.1 for MP2; 8.41, 18.3, 17.2 and 18.3 for MP4; 9.41, 5.98, 4.85 and 6.90 for G2(MP2) and 6.69, 4.06, 3.85 and 4.60 kJ·mol-1 for G2, respectively. It is clear that the MP2 calculation did quite poor for all of the foux categories of reactions and the MP4 did well only for the isoelectronic and isogyric reactions. The G2(MP2) and G2 reproduce the eaperimental reaction enthalpy changes very well for all reactions in the four categories展开更多
In this study, the energy for the ground state of helium and a few helium-like ions （Z=1-6） is computed variationally by using a Hylleraas-like wavefunction. A four-parameters wavefunction, satisfying boundary condi...In this study, the energy for the ground state of helium and a few helium-like ions （Z=1-6） is computed variationally by using a Hylleraas-like wavefunction. A four-parameters wavefunction, satisfying boundary conditions for coalescence points, is combined with a Hylleraas-like basis set which explicitly incorporates r12 interelectronic distance. The main contribution of this work is the introduction of modified correlation terms leading to the definition of integral transforms which provide the calculation of expectation value of energy to be done analytically over single-particle coordinates instead of Hylleraas coordinates.展开更多
In this paper, resonance energies and excitation energies of doubly 2<em>sns</em> <sup>1,3</sup><em>S</em><sup>e</sup>, 2<em>snp</em> <sup>1,3</sup&...In this paper, resonance energies and excitation energies of doubly 2<em>sns</em> <sup>1,3</sup><em>S</em><sup>e</sup>, 2<em>snp</em> <sup>1,3</sup><em>P</em><sup>0</sup>, 2<em>pnp</em> <sup>1,3</sup><em>D</em><sup>e</sup>, 2<em>pnd</em> <sup>1,3</sup><em>F</em><sup>0</sup> and 2<em>pnf</em> <sup>1,3</sup><em>G</em><sup>e</sup> excited states of the helium isoelectronic sequence with <em>Z</em> <span style="white-space:nowrap;">≤</span> 10 are calculated. Calculations are carried out in the framework of the variational procedure of the formalism of the Screening Constant per Unit Nuclear Charge (SCUNC). New correlated wave function of Hylleraas type is used. Precise resonance and excitation energies are tabulated and good agreement is obtained when a comparison is made with available literature values.展开更多
Using ab initio density functional theory calculations, we explore the three most stable structural phases, namely, α,β, and cubic(c) phases, of two-dimensional(2D) antimonene, as well as its isoelectronic counterpa...Using ab initio density functional theory calculations, we explore the three most stable structural phases, namely, α,β, and cubic(c) phases, of two-dimensional(2D) antimonene, as well as its isoelectronic counterparts SnTe and InI. We find that the band gap increases monotonically from Sb to SnTe to InI along with an increase in ionicity, independent of the structural phases. The band gaps of this material family cover the entire visible-light energy spectrum, ranging from 0.26 eV to 3.37 eV, rendering them promising candidates for optoelectronic applications. Meanwhile, band-edge positions of these materials are explored and all three types of band alignments can be achieved through properly combining antimonene with its isoelectronic counterparts to form heterostructures. The richness in electronic properties for this isoelectronic material family sheds light on possibilities to tailor the fundamental band gap of antimonene via lateral alloying or forming vertical heterostructures.展开更多
We report in this paper the ground-state energy 2s^(2)^(1)S and total energies of doubly excited states 2p^(2)^(1)D,3d^(2)^(1)D,4f^(2)^(1)I of the Helium isoelectronic sequence from H-to Ca^(18+).Calculations are perf...We report in this paper the ground-state energy 2s^(2)^(1)S and total energies of doubly excited states 2p^(2)^(1)D,3d^(2)^(1)D,4f^(2)^(1)I of the Helium isoelectronic sequence from H-to Ca^(18+).Calculations are performed using the Modified Atomic Orbital Theory(MAOT)in the framework of a variational procedure.The purpose of this study required a mathematical development of the Hamiltonian applied to Slater-type wave function[1]combining with Hylleraas-type wave function[2].The study leads to analytical expressions which are carried out under special MAXIMA computational program.This first proposed MAOT variational procedure,leads to accurate results in good agreement as well as with available other theoretical results than experimental data.In the present work,a new correlated wave function is presented to express analytically the total energies for the 2s21S ground state and each doubly 2p^(2)^(1)D,3d^(2)^(1)D,4f^(2)^(1)I excited states in the He-like systems.The present accurate data may be a useful guideline for future experimental and theoretical studies in the(nI^(2))systems.展开更多
The nonrelativistic dipole-length, -velocity and -acceleration absorptionoscillator strengths for the 1s~22s-1s~22p transitions of the lithium isoelectronic sequence from Z= 11 to 20 are calculated by using the energi...The nonrelativistic dipole-length, -velocity and -acceleration absorptionoscillator strengths for the 1s~22s-1s~22p transitions of the lithium isoelectronic sequence from Z= 11 to 20 are calculated by using the energies and the multiconfiguration interaction wavefunctions obtained from a full core plus correlation (FCPC) method. In most cases, the agreementbetween the oscillator strengths values from the length and velocity formula is up to four or fivedigit. Our results are aiso in good agreement with previous theoretical data available in theliterature.展开更多
Under heavy nitrogen doping,due to the “concentration quenching” effect,the full spectrum of the NN 3 center is revealed without the interference from the spectra of other higher energy centers.This investigation o...Under heavy nitrogen doping,due to the “concentration quenching” effect,the full spectrum of the NN 3 center is revealed without the interference from the spectra of other higher energy centers.This investigation offers a direct proof for that all the phonon replicas are the phonon sidebands governed by the Huang Rhys’ multiphonon optical transition theory.展开更多
Zintl-phase compounds have great potential in thermoelectric applications owing to their“phonon glasselectron crystal”(PGEC)structures.In this paper,a new Zintlphase thermoelectric material Ba Ag Sb is reported.Ba d...Zintl-phase compounds have great potential in thermoelectric applications owing to their“phonon glasselectron crystal”(PGEC)structures.In this paper,a new Zintlphase thermoelectric material Ba Ag Sb is reported.Ba deficiency increased the carrier concentration,and then suppressed the intrinsic excitation.The peak ZT value of Ba_(0.98)Ag Sb reached~0.56 at 773 K.Moreover,Eu alloying at Ba site not only lowered the lattice thermal conductivity by inducing point-defect scattering,but also improved the electrical properties by increasing the carrier mobility.Finally,a peak ZT of~0.73 was achieved in Ba_(0.78)Eu_(0.2)Ag Sb.展开更多
The polarizabilities and hyperpolarizabilities of the tetrahydropyrrole diradical in different electronic states have been investigated using ab initio and density functional theory （DFT） methods combined with the f...The polarizabilities and hyperpolarizabilities of the tetrahydropyrrole diradical in different electronic states have been investigated using ab initio and density functional theory （DFT） methods combined with the finite field （FF） approach. The polarizability average value as is a maximum for the singlet state, while that for the closed-shell is a minimum. The trend in second hyperpolarizability average value yis in good agreement with that for as The yvalues of the singlet and triplet states are, respectively, about 3 and 2 times larger than that of the closed-shell. The order of the first hyperpolarizability total effective value βtot is βot （closed shell） βtot （singlet） 〉 βtot （triplet）. The as, βtot, and 7 values of different electronic states obtained using the B3LYP and MP4SDQ methods are close to those obtained using the reliable CCSD method. The nonlinear optical （NLO） properties of two systems isoelectronic with the tetrahydropyrrole diradical-cyclopentane and tetrahydrofuran diradicalsshow that the polarizabilities and hyperpolarizabilities of these systems are all smaller than those of the tetrahydropyrrole diradical in the three electronic states.展开更多
The electrostatic potential of carbene and nitrene,have been calculated by AB INITIO method with 6-31G** basis set,there are positive potential regions in the directions of vacant P orbitals,and negative regions in th...The electrostatic potential of carbene and nitrene,have been calculated by AB INITIO method with 6-31G** basis set,there are positive potential regions in the directions of vacant P orbitals,and negative regions in the directions of lone-pair electrons. Therefore,atoms in these molecules have different electric properties in different directions.The idea of electrophilic and nucleophilic directions of an atom in molecules should be introduced.展开更多
The transitions of E0 ,E0 ＋A0, and E＋ in dilute GaAs（1-x） Nx alloys with x = 0.10% ,0.22% ,0.36% ,and 0.62% are observed by micro-photoluminescence. Resonant Raman scattering results further confirm that they are ...The transitions of E0 ,E0 ＋A0, and E＋ in dilute GaAs（1-x） Nx alloys with x = 0.10% ,0.22% ,0.36% ,and 0.62% are observed by micro-photoluminescence. Resonant Raman scattering results further confirm that they are from the intrinsic emissions in the studied dilute GaAsN alloys rather than some localized exciton emissions in the GaAsN alloys. The results show that the nitrogen-induced E E＋ and E0 ＋ A0 transitions in GaAsN alloys intersect at a nitrogen content of about 0.16%. It is demonstrated that a small amount of isoelectronic doping combined with micro-photoluminescence allows direct observation of above band gap transitions that are not usually accessible in photoluminescence.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10774063)
文摘The dipole-length, dipole-velocity and dipole-acceleration absorption oscillator strengths for the 1s^22s-1s^2np （3 ≤ n ≤9） transitions of lithium-like systems from Z = 11 to 20 are calculated by using the energies and the multiconfiguration interaction wave functions obtained from a full core plus correlation method, in which relativistic and mass-polarization effects on the energy, as the first-order perturbation corrections, are included. The results of three forms are in good agreement with each other, and closely agree with the experimental data available in the literature. Based on the quantum defects obtained with quantum defect theory （QDT）, the discrete oscillator strengths for the transitions from the ground state to highly excited states 1s^2np （n ≥ 10） and oscillator strength densities corresponding to the bound-free transitions are obtained for these ions.
文摘Enthalpy changes of the reactions involved in our previous papers have been re-examined at the G2(MP2) and G2 levels. The G2(MP2) and G2 energies of Ar, Ar+,ArAr+, ArCl+, ArF+, ArH+, ArHe+, ArNe+, ArO+, ArS+, H2+, He, HeCl+, HeF+, HeO+,HeS+, Ne, NeCl+, NeF+, NeO+ and NeS+ have been calculated. The G2(MP2) and G2 results for all of the interested reactions have also been compared with those of the previous MP2/6-31G** and MP4/6-311G (2df, 2pd) calculations. All of the G2(MP2) and G2 reaction enthalpies are improved from the MP2 and MP4 level of calculations when compared with the experimental data for the four categories of reactions as (1) iso-electronic, isogyric; (2) valence isoelectronic, isogyric; (3) isogyric and (4)non-isogyric reactions with the average absolute deviations of 5.10, 4.60, 7.70 and 9.20 for G2(MP2) and 4.18, 5.19, 6.78 and 6.49kJ·mol-1 for G2, respectively. The individural deviation for almost all of the reactions involved in this work is not more than±13kJ·mol-1 for G2(MP2) and ±8.4kJ·mol-1 for G2. In this paper, an additional number of reactions examined at the G2(MP2) and G2 levels as well as at the MP2/6-31G** and MP4/6-311G (2df, 2pd) levels of calculations have also been reported. The MP2, MP4, G2(MP2) and G2 total energies for the interested chemical species have been calculated if these energies have not been reported in literatures. All of the reaction energies at different levels have been compared with the experimental data in a nummber of reactions devided into the above four categories. The average absolute deviations are 25.9, 36.0, 29.2 and 40.1 for MP2; 8.41, 18.3, 17.2 and 18.3 for MP4; 9.41, 5.98, 4.85 and 6.90 for G2(MP2) and 6.69, 4.06, 3.85 and 4.60 kJ·mol-1 for G2, respectively. It is clear that the MP2 calculation did quite poor for all of the foux categories of reactions and the MP4 did well only for the isoelectronic and isogyric reactions. The G2(MP2) and G2 reproduce the eaperimental reaction enthalpy changes very well for all reactions in the four categories
基金Project supported by the Cumhuriyet University National MOVPE Crystal Growth and Characterization Laboratory,DPT-K120,TUBITAK (Grant Nos TBAG 105T492,TBAG 107T012,and TBAG-108T015)
文摘In this study, the energy for the ground state of helium and a few helium-like ions （Z=1-6） is computed variationally by using a Hylleraas-like wavefunction. A four-parameters wavefunction, satisfying boundary conditions for coalescence points, is combined with a Hylleraas-like basis set which explicitly incorporates r12 interelectronic distance. The main contribution of this work is the introduction of modified correlation terms leading to the definition of integral transforms which provide the calculation of expectation value of energy to be done analytically over single-particle coordinates instead of Hylleraas coordinates.
文摘In this paper, resonance energies and excitation energies of doubly 2<em>sns</em> <sup>1,3</sup><em>S</em><sup>e</sup>, 2<em>snp</em> <sup>1,3</sup><em>P</em><sup>0</sup>, 2<em>pnp</em> <sup>1,3</sup><em>D</em><sup>e</sup>, 2<em>pnd</em> <sup>1,3</sup><em>F</em><sup>0</sup> and 2<em>pnf</em> <sup>1,3</sup><em>G</em><sup>e</sup> excited states of the helium isoelectronic sequence with <em>Z</em> <span style="white-space:nowrap;">≤</span> 10 are calculated. Calculations are carried out in the framework of the variational procedure of the formalism of the Screening Constant per Unit Nuclear Charge (SCUNC). New correlated wave function of Hylleraas type is used. Precise resonance and excitation energies are tabulated and good agreement is obtained when a comparison is made with available literature values.
基金Project supported by the National Natural Science Foundation of China(Grant No.51702146)the College Students’Innovation and Entrepreneurship Projects,China(Grant No.201710148000072)Liaoning Province Doctor Startup Fund,China(Grant No.201601325)。
文摘Using ab initio density functional theory calculations, we explore the three most stable structural phases, namely, α,β, and cubic(c) phases, of two-dimensional(2D) antimonene, as well as its isoelectronic counterparts SnTe and InI. We find that the band gap increases monotonically from Sb to SnTe to InI along with an increase in ionicity, independent of the structural phases. The band gaps of this material family cover the entire visible-light energy spectrum, ranging from 0.26 eV to 3.37 eV, rendering them promising candidates for optoelectronic applications. Meanwhile, band-edge positions of these materials are explored and all three types of band alignments can be achieved through properly combining antimonene with its isoelectronic counterparts to form heterostructures. The richness in electronic properties for this isoelectronic material family sheds light on possibilities to tailor the fundamental band gap of antimonene via lateral alloying or forming vertical heterostructures.
文摘We report in this paper the ground-state energy 2s^(2)^(1)S and total energies of doubly excited states 2p^(2)^(1)D,3d^(2)^(1)D,4f^(2)^(1)I of the Helium isoelectronic sequence from H-to Ca^(18+).Calculations are performed using the Modified Atomic Orbital Theory(MAOT)in the framework of a variational procedure.The purpose of this study required a mathematical development of the Hamiltonian applied to Slater-type wave function[1]combining with Hylleraas-type wave function[2].The study leads to analytical expressions which are carried out under special MAXIMA computational program.This first proposed MAOT variational procedure,leads to accurate results in good agreement as well as with available other theoretical results than experimental data.In the present work,a new correlated wave function is presented to express analytically the total energies for the 2s21S ground state and each doubly 2p^(2)^(1)D,3d^(2)^(1)D,4f^(2)^(1)I excited states in the He-like systems.The present accurate data may be a useful guideline for future experimental and theoretical studies in the(nI^(2))systems.
基金The project supported by National Natural Science Foundation of China under Grant Nos.10347114,10174029the China Postdoctoral Science Foundation
文摘The nonrelativistic dipole-length, -velocity and -acceleration absorptionoscillator strengths for the 1s~22s-1s~22p transitions of the lithium isoelectronic sequence from Z= 11 to 20 are calculated by using the energies and the multiconfiguration interaction wavefunctions obtained from a full core plus correlation (FCPC) method. In most cases, the agreementbetween the oscillator strengths values from the length and velocity formula is up to four or fivedigit. Our results are aiso in good agreement with previous theoretical data available in theliterature.
文摘Under heavy nitrogen doping,due to the “concentration quenching” effect,the full spectrum of the NN 3 center is revealed without the interference from the spectra of other higher energy centers.This investigation offers a direct proof for that all the phonon replicas are the phonon sidebands governed by the Huang Rhys’ multiphonon optical transition theory.
基金supported by the National Natural Science Foundation of China (51871081, 11674078, 51971081, and 52001339)the Cheung Kong Scholar Reward Program Young Scholar Program of China (Q2018239)+3 种基金the Natural Science Foundation of Guangdong Province of China (2018A0303130033)the Natural Science Foundation for Distinguished Young Scholars of Guangdong Province (2020B1515020023)Shenzhen Science and Technology Innovation Plan (KQJSCX20180328165435202 and JCYJ20180307154619840)the National Key Research and Development Program of China (2017YFA0303600)
文摘Zintl-phase compounds have great potential in thermoelectric applications owing to their“phonon glasselectron crystal”(PGEC)structures.In this paper,a new Zintlphase thermoelectric material Ba Ag Sb is reported.Ba deficiency increased the carrier concentration,and then suppressed the intrinsic excitation.The peak ZT value of Ba_(0.98)Ag Sb reached~0.56 at 773 K.Moreover,Eu alloying at Ba site not only lowered the lattice thermal conductivity by inducing point-defect scattering,but also improved the electrical properties by increasing the carrier mobility.Finally,a peak ZT of~0.73 was achieved in Ba_(0.78)Eu_(0.2)Ag Sb.
基金supported by the National Natural Science Foundation of China (20873017)the Program for Changjiang Scholars and Innovative Research Teams in University (IRT0714)
文摘The polarizabilities and hyperpolarizabilities of the tetrahydropyrrole diradical in different electronic states have been investigated using ab initio and density functional theory （DFT） methods combined with the finite field （FF） approach. The polarizability average value as is a maximum for the singlet state, while that for the closed-shell is a minimum. The trend in second hyperpolarizability average value yis in good agreement with that for as The yvalues of the singlet and triplet states are, respectively, about 3 and 2 times larger than that of the closed-shell. The order of the first hyperpolarizability total effective value βtot is βot （closed shell） βtot （singlet） 〉 βtot （triplet）. The as, βtot, and 7 values of different electronic states obtained using the B3LYP and MP4SDQ methods are close to those obtained using the reliable CCSD method. The nonlinear optical （NLO） properties of two systems isoelectronic with the tetrahydropyrrole diradical-cyclopentane and tetrahydrofuran diradicalsshow that the polarizabilities and hyperpolarizabilities of these systems are all smaller than those of the tetrahydropyrrole diradical in the three electronic states.
基金This work is supported by Scientific Fund of the Chinese Academy of Science.
文摘The electrostatic potential of carbene and nitrene,have been calculated by AB INITIO method with 6-31G** basis set,there are positive potential regions in the directions of vacant P orbitals,and negative regions in the directions of lone-pair electrons. Therefore,atoms in these molecules have different electric properties in different directions.The idea of electrophilic and nucleophilic directions of an atom in molecules should be introduced.
文摘The transitions of E0 ,E0 ＋A0, and E＋ in dilute GaAs（1-x） Nx alloys with x = 0.10% ,0.22% ,0.36% ,and 0.62% are observed by micro-photoluminescence. Resonant Raman scattering results further confirm that they are from the intrinsic emissions in the studied dilute GaAsN alloys rather than some localized exciton emissions in the GaAsN alloys. The results show that the nitrogen-induced E E＋ and E0 ＋ A0 transitions in GaAsN alloys intersect at a nitrogen content of about 0.16%. It is demonstrated that a small amount of isoelectronic doping combined with micro-photoluminescence allows direct observation of above band gap transitions that are not usually accessible in photoluminescence.
