LMP2 converence problems

[pulkin]

LMP2, generally, converges only down to a limitedly small value. The reason may be improper transformation when transforming residuals into updated amplitudes.

local-pyscf/lmp2.py

Lines 101 to 111 in 7fca442

	basis = fock_basis_local[k]
	virt_e = fock_energies_local[k]
	# dual = numpy.linalg.inv(basis).T
	v = common.transform(v, basis)
	denominator = fock_occ[k[0], k[0]] + fock_occ[k[1], k[1]] - virt_e[:, numpy.newaxis] - virt_e[numpy.newaxis, :]
	dt = v / denominator
	dt_pao = common.transform(dt, basis.T)
	result[k] = dt_pao
	t2_diff = max(t2_diff, numpy.abs(dt_pao).max())