{"currentpage":1,"firstResult":0,"maxresult":10,"pagecode":5,"pageindex":{"endPagecode":5,"startPagecode":1},"records":[{"abstractinfo":"An improvement of ligand-field theory has been developed. Based on our theory of pressure-induced shifts and the diagonalization of the complete energy matrix, the unified calculation of;he whole energy spectrum and g factors of the ground state at normal pressure and their pressure-induced shifts has been carried out. All the calculated results for alpha-Al2O3:V3+ are in very good agreement with a great number of experimental data. It Is found that the distinct differences in magnitude and/or sign for pressure-induced shifts of various levels are immediately determined by characteristic dependencies of levels on the parameters of interactions, and the pressure-induced shifts of levels can provide definite or crucial criteria for the correctness of assignments and <span style=\"color:red\">calculations</span> of them.","authors":[],"categoryName":"|","doi":"","fpage":"1780","id":"88990754-e7b1-4881-886e-0d6cbd819815","issue":"4","journal":{"abbrevTitle":"PRB","id":"41d73232-e732-4216-a5f7-4b352bb955cf","issnPpub":"0163-1829","publisherId":"PRB","title":"Physical Review B"},"keywords":[{"id":"e750d29d-cf61-4258-9b5f-9e81a9c20dd4","keyword":"<span style=\"color:red\">theoretical</span> <span style=\"color:red\">calculations</span>;<span style=\"color:red\">ruby</span>","originalKeyword":"theoretical calculations;ruby"}],"language":"en","publisherId":"0163-1829_1997_4_1","title":"Pressure-induced shifts of energy levels of alpha-Al2O3:V3+ and a complete ligand-field calculation","volume":"56","year":"1997"},{"abstractinfo":"By taking into account the effect of variation in angular wavefunction, by reconsidering the expressions of spin-orbit coupling parameters, by diagonalizing the complete d(3) energy matrix in a trigonally distorted cubic-field and using the wavefunctions from it, the unified calculation of the whole energy spectrum and EPR spectrum for <span style=\"color:red\">ruby</span> and their pressure-induced shifts was carried out. All the calculated results are in very good agreement with a lot of the optical and EPR experimental data. The estimation by use of superposition model has also demonstrated the reality of calculated results and the high sensitivity of trigonal-field parameters to angular variation. The rates of change of levels with respect to various parameters, the variations of parameters with pressure and the contributions to levels from various parameters were calculated. The distinct differences in magnitude and/or sign of pressure-induced shifts of various levels are immediately determined by their characteristic dependencies on the parameters of interactions. The pressure-induced shifts of levels and g factors have provided important criteria for the correctness of <span style=\"color:red\">calculations</span> and assignments of the energy spectrum and wavefunctions. (C) 1999 Elsevier Science Ltd. All rights reserved.","authors":[],"categoryName":"|","doi":"","fpage":"463","id":"6f187e71-5ae1-4e76-b48f-7980071c990d","issue":"4","journal":{"abbrevTitle":"JOPACOS","id":"6268f571-fbc6-4d83-a6ed-a357d820c3df","issnPpub":"0022-3697","publisherId":"JOPACOS","title":"Journal of Physics and Chemistry of Solids"},"keywords":[{"id":"9f2956a2-43e3-4f0a-8cff-17c8b48ccf6f","keyword":"optical materials;high pressure;crystal fields;optical properties;electronic paramagnetic resonance (EPR);entire energy-spectrum;r-lines;superposition-model;crystal fields;dependence;state;absorption;equation;cr3+;gpa","originalKeyword":"optical materials;high pressure;crystal fields;optical properties;electronic paramagnetic resonance (EPR);entire energy-spectrum;r-lines;superposition-model;crystal fields;dependence;state;absorption;equation;cr3+;gpa"}],"language":"en","publisherId":"0022-3697_1999_4_1","title":"<span style=\"color:red\">Theoretical</span> <span style=\"color:red\">calculations</span> of optical and EPR spectra and their pressure-induced shifts for <span style=\"color:red\">ruby</span>","volume":"60","year":"1999"},{"abstractinfo":"On the basis of the unified calculation of the thermal shifts of R-1 line, R-2 line and ground-state-splitting as well as the thermal broadenings of R, R' and B line-groups for <span style=\"color:red\">ruby</span>, by taking into account all the levels and admixtures of wavefunctions within d(3) electronic configuration and all the GammaM in electron-phonon interaction, the transition probabilities of direct and Raman processes have theoretically been calculated. The thermal broadenings, of R, R' and B line-groups have successfully been interpreted in terms of the direct and Raman processes of acoustic phonons. The theoretically predicted transition probabilities are in good agreement with the experimental ones.","authors":[],"categoryName":"|","doi":"","fpage":"723","id":"06f59047-818d-46de-832b-cbacb5b1382a","issue":"6","journal":{"abbrevTitle":"CITP","id":"45f28bf6-874e-4b98-936f-4562e2c56a77","issnPpub":"0253-6102","publisherId":"CITP","title":"Communications in Theoretical Physics"},"keywords":[{"id":"9b63d2db-79e5-49e1-aec7-a659c330a4d0","keyword":"crystal fields;electron-phonon interaction;thermal broadening;transition probability;direct and Raman processes;shifts","originalKeyword":"crystal fields;electron-phonon interaction;thermal broadening;transition probability;direct and Raman processes;shifts"}],"language":"en","publisherId":"0253-6102_2001_6_2","title":"<span style=\"color:red\">Theoretical</span> <span style=\"color:red\">calculations</span> of thermal broadenings and transition probabilities of R, R ' and B line-groups for <span style=\"color:red\">ruby</span>","volume":"36","year":"2001"},{"abstractinfo":"The d(3) ions in trigonal crystal fields are considered. On the basis of the expansion of the electron wavefunctions under pressure, the expressions for the parameters Dq, B, C, K, K' and zeta as functions of the linear compression ratio chi are derived, and the complete d(3) energy matrix in trigonal field is constructed. With the P-(chi) dependence, by diagonalization of this matrix to fit only the experimental data of the red shifts of <span style=\"color:red\">ruby</span> R(1) line under quasihydrostatic pressure, the values of three parameters for the pressure shift (S-0, D-1 and t) are determined. Then, the values of Dq, B, C, K, K' and zeta at various pressures are evaluated, and the pressure shifts of the entire energy spectrum of <span style=\"color:red\">ruby</span> are theoretically calculated uniformly by diagonalization of the complete d(3) matrix. The contributions of changes of Dq, B, C, R, K' and zeta to the R(1) and R(2) red shifts and the pressure-induced change in the R(1)-R(2) Splitting are obtained. The calculated results of the pressure shifts are in good agreement with ail the experimental data of the R-, R'- and B-line groups and U and Y bands. A discussion is given and conclusions drawn.","authors":[],"categoryName":"|","doi":"","fpage":"4883","id":"39583829-575c-45a1-a04f-9e2f9eea2253","issue":"25","journal":{"abbrevTitle":"JOPM","id":"f0e359df-48a6-4a7f-b16d-2389d3e793ee","issnPpub":"0953-8984","publisherId":"JOPM","title":"Journal of Physics-Condensed Matter"},"keywords":[{"id":"c2b14d36-e024-45d7-8214-0a5cd68934be","keyword":"line thermal-shift;r-lines;calibration;dependence;gauge;kbar;gpa","originalKeyword":"line thermal-shift;r-lines;calibration;dependence;gauge;kbar;gpa"}],"language":"en","publisherId":"0953-8984_1995_25_1","title":"<span style=\"color:red\">THEORETICAL</span> <span style=\"color:red\">CALCULATIONS</span> OF PRESSURE-INDUCED SHIFTS OF THE ENTIRE ENERGY-SPECTRUM OF <span style=\"color:red\">RUBY</span>","volume":"7","year":"1995"},{"abstractinfo":"By taking into account all the irreducible representations and their components in the electron-phonon interaction (EPI) as well as all the levels and the admixtures of wavefunctions within d(3) electronic configuration, the thermal shifts (TS) of the ground-state zero-field-splitting (GSZFS) due to EPI for <span style=\"color:red\">ruby</span> have microscopic-theoretically been calculated; the contribution to TS of GSZFS from thermal expansion has also been calculated. The results are in very good agreement with experiments. It is found that the contributions from the first-order perturbation of the second-order term in EPI Hamiltonian are dominant in the Raman term and optical-branch term for TS of GSZFS; the different between the TS due to EPI of t(2)(3 4)A(2) +/-1/2e(2) (G(2)) level and the TS due to EPI of t(2)(3) (4)A(2) +/- 3/2e(2) (G(1)) level gives rise to the TS due to EPI of GSZFS, which is very small in comparison with the TS due to EPI of G(2) or G(1) level. Among various terms in TS of GSZFS, Raman term is the largest one and the signs of the Raman term and optical-branch term are opposite to the sign of the thermal-expansion term; the optical-branch term plays an important role in TS of GSZFS and increases rapidly with temperature; all various contributions to TS of GSZFS have to be taken into account, since the subtle balance among them determines the total result. The comparison between the features of TS of GSZFS and those of TS of R-1 and R-2 lines has been made. For TS of GSZFS, the contribution from thermal expansion is especially important; the neighbor-level term is insignificant.","authors":[],"categoryName":"|","doi":"","fpage":"357","id":"f542ed99-d5aa-4122-b6b0-a803f0a05b9b","issue":"3","journal":{"abbrevTitle":"CITP","id":"45f28bf6-874e-4b98-936f-4562e2c56a77","issnPpub":"0253-6102","publisherId":"CITP","title":"Communications in Theoretical Physics"},"keywords":[{"id":"a257ae0d-60fa-4ba1-9953-7ca2028397c1","keyword":"optical materials;crystal fields;electronic paramagnetic resonance;phonons;thermal expansion;pressure-induced shifts;optical-spectra;mgo-v2+","originalKeyword":"optical materials;crystal fields;electronic paramagnetic resonance;phonons;thermal expansion;pressure-induced shifts;optical-spectra;mgo-v2+"}],"language":"en","publisherId":"0253-6102_2001_3_2","title":"<span style=\"color:red\">Theoretical</span> <span style=\"color:red\">calculations</span> of thermal shifts of ground-state zero-field-splitting for <span style=\"color:red\">ruby</span>","volume":"36","year":"2001"},{"abstractinfo":"A new theory of spectral thermal shifts (TS) has been developed. For the first time, by taking into account all the irreducible representations and their components in the electron-phonon interaction (EPI), all the levels and the admixtures of wavefunctions within d(3) electronic configuration, the microscopic expressions for all the parameters in Raman, neighbor-level and optical-branch terms of TS due to EPI have been derived; their values for the R-1, R-2 and ground levels of <span style=\"color:red\">ruby</span> have been evaluated; the contributions to TS from thermal expansion have also been calculated; and then, the unified calculation of the TS of R-1 and R-2 lines and zero-field splitting (ZFS) for the ground state and the thermal broadenings of R, R' and B line-groups have successfully been accomplished. It is found that the contributions from the second-order term of EPI Hamiltonian H-(2) are dominant in Raman terms of R-1 and R-2 lines; the optical-branch terms play an important role in TS and increase rapidly with temperature and the ones of R-1 and R-2 lines have opposite signs due to the effects of neighbor levels; the neighbor-level terms are very important and it is the admixtures of wavefunctions caused by Coulomb interaction between d electrons and/or trigonal-field and/or spin-orbit interactions that make them nonzero; the contributions to TS from thermal expansion are also important. (C) 2000 Elsevier Science Ltd. All rights reserved.","authors":[],"categoryName":"|","doi":"","fpage":"799","id":"ec79cbd0-0f35-4d75-b8a2-fdb3e4f11d7b","issue":"5","journal":{"abbrevTitle":"JOPACOS","id":"6268f571-fbc6-4d83-a6ed-a357d820c3df","issnPpub":"0022-3697","publisherId":"JOPACOS","title":"Journal of Physics and Chemistry of Solids"},"keywords":[{"id":"d8ed5149-4ac1-43ab-9126-44b102549769","keyword":"crystal fields;optical properties;phonons;electronic structure;thermal expansion;diamond-anvil cell;entire energy-spectrum;r-line;pressure;measurement;temperature;spectroscopy;calibration;dependence","originalKeyword":"crystal fields;optical properties;phonons;electronic structure;thermal expansion;diamond-anvil cell;entire energy-spectrum;r-line;pressure;measurement;temperature;spectroscopy;calibration;dependence"}],"language":"en","publisherId":"0022-3697_2000_5_1","title":"<span style=\"color:red\">Theoretical</span> <span style=\"color:red\">calculations</span> of thermal shifts and thermal broadenings of sharp lines and zero-field splitting for <span style=\"color:red\">ruby</span>. Part I. Thermal shifts of R-1 and R-2 lines","volume":"61","year":"2000"},{"abstractinfo":"By taking into account the effect of variation in angular wavefunction, reconsidering the expressions of spin-orbit coupling parameters, diagonalizing the complete d(3) energy matrix in a trigonally distorted cubic-field and using the wavefunctions from it, the unified <span style=\"color:red\">calculations</span> of the energy spectrum and EPR spectrum for <span style=\"color:red\">ruby</span> and their pressure-induced shifts have been carried out. All the calculated results are in very good agreement with a lot of experimental data. The estimation by making use of superposition model has also demonstrated the high sensitivity of trigonal-field parameters to angular variation. The distinct differences in magnitude and/or sign of pressure-induced shifts of various levels are immediately determined by their characteristic dependencies on the parameters of interactions. The pressure-induced shifts of levels and g factors have provided important criteria for the correctness of <span style=\"color:red\">calculations</span> and assignments of the energy spectrum and wavefunctions.","authors":[],"categoryName":"|","doi":"","fpage":"327","id":"7b68e4c5-03a3-44d4-b3cf-a65ae765c7d9","issue":"3","journal":{"abbrevTitle":"CITP","id":"45f28bf6-874e-4b98-936f-4562e2c56a77","issnPpub":"0253-6102","publisherId":"CITP","title":"Communications in Theoretical Physics"},"keywords":[{"id":"c91d6a36-df4d-43c6-a488-0040be931515","keyword":"crystal field;energy spectra;electronic paramagnetic resonance;high;pressure;<span style=\"color:red\">theoretical</span> <span style=\"color:red\">calculations</span>;crystal fields;r-lines;state;dependence;absorption;equation;model;cr3+","originalKeyword":"crystal field;energy spectra;electronic paramagnetic resonance;high;pressure;theoretical calculations;crystal fields;r-lines;state;dependence;absorption;equation;model;cr3+"}],"language":"en","publisherId":"0253-6102_1999_3_1","title":"Unified <span style=\"color:red\">calculations</span> of the energy and EPR spectra and their pressure-induced shifts of <span style=\"color:red\">ruby</span>","volume":"31","year":"1999"},{"abstractinfo":"The R line and U band at normal pressure and their pressure-induced shifts of <span style=\"color:red\">ruby</span> have been calculated by making use of the SCF embedded-cluster discrete variational (DV-X-alpha) method. The calculated results of the spectral pressure-induced shifts of <span style=\"color:red\">ruby</span> by making use of the crystal-field theory have also been given. The results of the first-principle <span style=\"color:red\">calculations</span> are in very good agreement with the experimental data and the calculated results by using crystal-field theory. The results of local lattice relaxations around the Cr3+ ion are obtained by the DV-X-alpha <span style=\"color:red\">calculations</span>.","authors":[],"categoryName":"|","doi":"","fpage":"265","id":"9d36db06-6b9a-4cf5-a801-3506514bf85d","issue":"3","journal":{"abbrevTitle":"CITP","id":"45f28bf6-874e-4b98-936f-4562e2c56a77","issnPpub":"0253-6102","publisherId":"CITP","title":"Communications in Theoretical Physics"},"keywords":[{"id":"2a2282ff-df89-447f-93e3-a797b6333155","keyword":"efficient","originalKeyword":"efficient"}],"language":"en","publisherId":"0253-6102_1997_3_1","title":"The DV-X-alpha <span style=\"color:red\">calculations</span> of optical spectra and their pressure-induced shifts for <span style=\"color:red\">ruby</span>","volume":"28","year":"1997"},{"abstractinfo":"Detailed <span style=\"color:red\">theoretical</span> studies of the temperature dependence of the zero-held splitting [characterized by Delta D(T)=D(T)-D(0) or dD/dT] of <span style=\"color:red\">ruby</span> have been made by taking into account both the static contribution due to the thermal expansion of the lattice and the vibrational contribution due to the electron-phonon interaction. The static part is calculated by using the local thermal expansion coefficients alpha(i) in the vicinity of the Cr3+ ions, which are obtained from the local compressibilities sigma(i) and the well-known relation alpha(i)=C-v gamma sigma(i)/V. The vibrational part includes the contributions from the acoustic and optical phonons. As in specific-heat studies of crystals, the vibrational contribution of phonons of the acoustic branches is calculated using the long-wavelength approximation, and that of phonons of the optical branches is calculated using a single-frequency model. The calculated results show that, to explain satisfactorily the temperature dependence of the zero-field splitting (ZFS), all of the contributions from the thermal expansion and the electron-phonon interaction should be considered. The static contribution is due mainly to the variations of bond angles as the temperature changes, which results in the static part of the temperature dependence of ZFS being opposite in sign to the observed temperature dependence. Thus the contribution due to the thermal expansion cannot be regarded as the main one. Among the various contributions, the contribution of acoustic phonons is the greatest in magnitude, and it has the same sign as the observed value. The contribution of optical phonons is the smallest and yet cannot be ignored.","authors":[],"categoryName":"|","doi":"","fpage":"1117","id":"39148326-1c02-4281-bb5c-8a26ef20d952","issue":"2","journal":{"abbrevTitle":"PRB","id":"41d73232-e732-4216-a5f7-4b352bb955cf","issnPpub":"0163-1829","publisherId":"PRB","title":"Physical Review B"},"keywords":[{"id":"4aa4663b-e5b8-433f-99a0-b4d074038565","keyword":"alpha-liio3 crystals;superposition model;parameters;ions;impurities;spectra;epr","originalKeyword":"alpha-liio3 crystals;superposition model;parameters;ions;impurities;spectra;epr"}],"language":"en","publisherId":"0163-1829_1996_2_1","title":"<span style=\"color:red\">Theoretical</span> studies of the temperature dependence of zero-field splitting of Cr3+ centers in <span style=\"color:red\">ruby</span>","volume":"54","year":"1996"},{"abstractinfo":"This work presents a <span style=\"color:red\">theoretical</span> pressure dependence of the spin-orbit coupling parameters of <span style=\"color:red\">ruby</span> from the experimental pressure dependence of the Racah parameter B and the calculated pressure variation of the group overlap integral. It shows that zeta increases slightly but zeta' decreases slightly with pressure.","authors":[],"categoryName":"|","doi":"","fpage":"326","id":"d7276906-e096-48dd-9e5b-2a15de85890b","issue":"4","journal":{"abbrevTitle":"PLA","id":"7b364793-d718-49d5-9832-ec34f0748fdf","issnPpub":"0375-9601","publisherId":"PLA","title":"Physics Letters A"},"keywords":[{"id":"227cca90-04e4-4fb9-85b1-fe337696b24d","keyword":"<span style=\"color:red\">theoretical</span> <span style=\"color:red\">calculations</span>;crystal-structure;red shift;line;compression;spectrum","originalKeyword":"theoretical calculations;crystal-structure;red shift;line;compression;spectrum"}],"language":"en","publisherId":"0375-9601_1992_4_1","title":"PRESSURE-DEPENDENCE OF SPIN-ORBIT-COUPLING PARAMETERS OF <span style=\"color:red\">RUBY</span>","volume":"163","year":"1992"}],"totalpage":156,"totalrecord":1557}