1#! /usr/bin/env python3 2 3from pyscf import gto, scf, cc 4from pyscf.cc import ccsd_t 5 6mol = gto.Mole() 7mol.basis = 'aug-cc-pvdz' 8mol.atom = (('Ne', 0,0,0),) 9mol.verbose = 4 10mol.build() 11 12mf = scf.RHF(mol) 13mf.chkfile = 'scf.chk' 14ehf = mf.kernel() 15 16ccsd = cc.CCSD(mf) 17eccsd = ccsd.kernel()[0] 18ecorr_ccsdt = ccsd_t.kernel(ccsd, ccsd.ao2mo()) 19print("E(CCSD(T)) = {}".format(ehf+eccsd+ecorr_ccsdt)) 20