scf.py 文件源码

def updateDIIS(self,F,P):
        FPS =   dot([F,P,self.S])
        SPF =   self.adj(FPS) 
        # error must be in orthonormal basis
        error = dot([self.X,FPS-SPF,self.X]) 
        self.fockSet.append(self.F)
        self.errorSet.append(error) 
        numFock = len(self.fockSet)
        # limit subspace, hardcoded for now
        if numFock > 8:
            del self.fockSet[0] 
            del self.errorSet[0] 
            numFock -= 1
        B = np.zeros((numFock + 1,numFock + 1)) 
        B[-1,:] = B[:,-1] = -1.0
        B[-1,-1] = 0.0
        # B is symmetric
        for i in range(numFock):
            for j in range(i+1):
                B[i,j] = B[j,i] = \
                    np.real(np.trace(np.dot(self.adj(self.errorSet[i]),
                                                     self.errorSet[j])))
        residual = np.zeros(numFock + 1)
        residual[-1] = -1.0
        weights = np.linalg.solve(B,residual)

        # weights is 1 x numFock + 1, but first numFock values
        # should sum to one if we are doing DIIS correctly
        assert np.isclose(sum(weights[:-1]),1.0)

        F = np.zeros((self.nbasis,self.nbasis),dtype='complex')
        for i, Fock in enumerate(self.fockSet):
            F += weights[i] * Fock

        return F