Paper considers the calculation of the values of Gibbs derivatives on finite Abelian groups. The calculation procedure is based upon the decision diagram representation of functions defined on finite Abelian groups. A...Paper considers the calculation of the values of Gibbs derivatives on finite Abelian groups. The calculation procedure is based upon the decision diagram representation of functions defined on finite Abelian groups. Approach permits processing of large functions.展开更多
A new algorithm for unconstrained optimization is developed, by using the product form of the OCSSR1 update. The implementation is especially useful when gradient information is estimated by difference formulae. Preli...A new algorithm for unconstrained optimization is developed, by using the product form of the OCSSR1 update. The implementation is especially useful when gradient information is estimated by difference formulae. Preliminary tests show that new algorithm can perform well.展开更多
The complete harmonic vibrational force field of dimethylnitramine has been calculated at the Hartree-Fock level using 4-21G basis set.The harmonic force field was then scaled with scale factors previously derived fro...The complete harmonic vibrational force field of dimethylnitramine has been calculated at the Hartree-Fock level using 4-21G basis set.The harmonic force field was then scaled with scale factors previously derived from N-methylnitramine,and the vibrational spectrum of dimethylnitramine was computed.This apriori prediction,made with no reference to observations on dimethylnitramine, agrees with the experimental IR spectrum in gas phase with a mean deviation of 8.4 cm^(-1).Some of the scale factors were reoptimized by fitting of the computed force field to experimental data.The new set of scale factors reduced the mean deviation to 4.5 cm^(-1),and was used to predict the vibrational spectrum of deuterated form of dimethylnitramine(-6D).Dipole moment derivatives were also cal- culated and used to predict infrared intensities which are comparable with experimental values.展开更多
文摘Paper considers the calculation of the values of Gibbs derivatives on finite Abelian groups. The calculation procedure is based upon the decision diagram representation of functions defined on finite Abelian groups. Approach permits processing of large functions.
文摘A new algorithm for unconstrained optimization is developed, by using the product form of the OCSSR1 update. The implementation is especially useful when gradient information is estimated by difference formulae. Preliminary tests show that new algorithm can perform well.
基金Project supported by the National Natural Science Foundation of China.
文摘The complete harmonic vibrational force field of dimethylnitramine has been calculated at the Hartree-Fock level using 4-21G basis set.The harmonic force field was then scaled with scale factors previously derived from N-methylnitramine,and the vibrational spectrum of dimethylnitramine was computed.This apriori prediction,made with no reference to observations on dimethylnitramine, agrees with the experimental IR spectrum in gas phase with a mean deviation of 8.4 cm^(-1).Some of the scale factors were reoptimized by fitting of the computed force field to experimental data.The new set of scale factors reduced the mean deviation to 4.5 cm^(-1),and was used to predict the vibrational spectrum of deuterated form of dimethylnitramine(-6D).Dipole moment derivatives were also cal- culated and used to predict infrared intensities which are comparable with experimental values.
