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