Patent ID: 8082131

Claim:
An electronic state calculation method performed by an electronic state calculation device including a CPU connected to memory storage, the electronic state calculation method for calculating an electronic state of a substance by a first-principle calculation, comprising the steps of: deciding a model to reproduce fluctuations of physical quantities characterizing physical properties of the substance using the electronic state calculation device; and obtaining the electronic state of the substance by the first-principle calculation with the decided model set as an initial condition using the electronic state calculation device, wherein the electronic state is obtained by using an optimization method based on an extended Kohn-Sham theory formulated by an expression including a residual exchange correlation energy functional expressed by the following equation: E rxc ⁡ [ n ψ ] = E xc ⁡ [ n ψ ] + min Φ → n Ψ ⁢ 〈 Φ ⁢  T  ⁢ Φ 〉 - min Ψ ′ → n Ψ ⁢ 〈 Ψ ′ ⁢  T + V red  ⁢ Ψ ′ 〉 wherein n Ψ indicates one-electron density, E xc [n Ψ ] indicates an exchange correlation energy functional, Φ indicates a many-particle wave function in a state in which correlation is not generated, Ψ′ indicates a many-particle wave function in a state in which the correlation is generated, T indicates a kinetic energy operator, and V red indicates an operator defined by the following correlation function given by a set of physical quantities {X i }: 〈 Ψ ⁢  V red  ⁢ Ψ 〉 = ∑ i ⁢ W i ⁢ 〈 Ψ ⁢  ( X i - X _ i ) · ( X i - X _ i )  ⁢ Ψ 〉 wherein i=1, 2, 3, . . . , N (N is the number of physical quantities to be calculated), W i indicates a parameter expressing a weight, and a symbol in a small parenthesis indicates a difference between the physical quantities X i and a mean value of the physical quantities X.