def initMPS(dmrg, debug=False):
if dmrg.comm.rank == 0: print '[mpo_dmrg_util.initMPS]'
# Product state MPS0
if dmrg.occun is None:
mps0 = mps0mixed(dmrg.dphys)
ifsym = False
else:
qnuml, qnumr, mps0 = mps0occun(dmrg.dphys, dmrg.occun, dmrg.isym)
dmrg.qnuml = copy.deepcopy(qnuml)
dmrg.qnumr = copy.deepcopy(qnumr)
ifsym = True
# DUMP
fmps0 = h5py.File(dmrg.path + '/mps0', 'w')
mpo_dmrg_io.dumpMPS(fmps0, mps0, icase=0)
if debug: dmrg.checkMPS(fmps0)
# init operators from mps
fnamel = dmrg.path + '/lop'
fnamer = dmrg.path + '/rop'
mpo_dmrg_init.genBops(dmrg, fnamel, dmrg.nops, -1, ifslc=False)
mpo_dmrg_init.genHops(dmrg, fmps0, fmps0, fnamer, 'R')
# Initialize MPS
sitelst = range(dmrg.nsite)
if debug:
mpo_dmrg_init.genHops(dmrg, fmps0, fmps0, fnamel, 'L')
mpo_dmrg_opt.sweep(dmrg, sitelst, dmrg.initNcsite, 'R', ifsym=ifsym)
# Initialization
mpo_dmrg_opt.sweep(dmrg, sitelst, dmrg.initNcsite, 'L', ifsym=ifsym)
# Nosym sweeps
for isweep in range(dmrg.initNsweep):
mpo_dmrg_opt.sweep(dmrg, sitelst, dmrg.initNcsite, 'R', ifsym=ifsym)
mpo_dmrg_opt.sweep(dmrg, sitelst, dmrg.initNcsite, 'L', ifsym=ifsym)
fmps0.close()
return 0
def vpt(dmrg):
rank = dmrg.comm.rank
# 1. LHS: Prepare operators for H0
dmrg.fdopXfhop()
hmat, smat = genCIHamiltonian(dmrg)
dmrg.fdopXfhop()
# 2. E0 = <Psi0|H|Psi0>
dmrg.nref = len(dmrg.wfex)
fbra = dmrg.wfex[0]
energy, esum, ovlp, psum = dmrg.checkMPS(fbra, fbra, ifprt=False)
# Normalization constant
if rank == 0:
dmrg.e0 = hmat[0, 0] / smat[0, 0]
dmrg.e1 = energy - dmrg.e0
dmrg.et = energy - dmrg.emix * dmrg.e1
dmrg.n0 = 1.0 / math.sqrt(smat[0, 0])
# 3. RHS = <0|H|psi1>
v01 = numpy.zeros(dmrg.nref)
for iref in range(1, dmrg.nref):
print '\n ### Hams: iref =', iref, ' rank= ', rank, '###'
fket = dmrg.wfex[iref]
# <A|H|B>
fnamel = dmrg.path + '/ref' + str(iref) + '_lhop'
fnamer = dmrg.path + '/ref' + str(iref) + '_rhop'
mpo_dmrg_init.genBops(dmrg, fnamer, dmrg.nops, dmrg.nsite, ifslc=True)
exphop = mpo_dmrg_init.genHops(dmrg, fbra, fket, fnamel, 'L')
hpwts = dmrg.fhop['wts'].value
esum = numpy.dot(hpwts, exphop)
esum = dmrg.comm.reduce(esum, op=MPI.SUM, root=0)
if rank == 0: v01[iref] = dmrg.n0 * esum.real
# 4. Solve <Psi1|H0E0|Psi1> = -<Psi1|V|Psi0>
if rank == 0:
ndim = hmat.shape[0]
Amat = (hmat - dmrg.et * smat)[numpy.ix_(range(1, ndim),
range(1, ndim))]
bvec = v01[1:]
cvec = scipy.linalg.solve(Amat, -bvec)
e2o = cvec.dot(bvec)
e2s = numpy.sum(bvec)
lhs = numpy.sum(Amat)
e2v = lhs + 2.0 * e2s
# L = <Psi1|H0-E0|Psi1>+2<Psi1|V|0>
print
print '=' * 40
print 'Summary of PT results: ifH0 =', dmrg.ifH0
print '=' * 40
print ' h0mat = \n', hmat
print ' smat = \n', smat
print ' emix =', dmrg.emix
print ' e0 = ', dmrg.e0
print ' e1 = ', dmrg.e1
print ' eH = ', energy
print ' et = ', dmrg.et
print ' n0 = ', dmrg.n0
print ' ndim =', ndim - 1
print ' Amat = \n', Amat
print ' bvec = \n', bvec
print ' (1) e2[ Sum of RHS ] =', e2s
print ' (2) e2[ Functional ] =', e2v
print ' * difference =', e2v - e2s
print ' * <Psi1|H0-E0|Psi1> =', lhs
print ' (3) e2[ ROptimized ] =', e2o
print ' * difference =', e2o - e2s
print ' * cvec =', cvec
e2 = e2o
#==========================================
# If the difference is large, then this
# indicate in the solution of psi1, the
# accuracy [D1] is not sufficiently high.
#==========================================
else:
e2 = None
cvec = None
return e2, cvec
def initOps(dmrg, fmps):
rank = dmrg.comm.rank
if rank == 0: print '\n[mpo_dmrg_util.initOps]'
#--------------------------------------------------------
# Initialization-0: normal initialization (lrop)
# H0 or H for LHS of eigenvalue or linear equations [PT]
#--------------------------------------------------------
if dmrg.ifpt and dmrg.ifH0: dmrg.fdopXfhop()
fnamel = dmrg.path + '/lop'
fnamer = dmrg.path + '/rop'
mpo_dmrg_init.genBops(dmrg, fnamer, dmrg.nops, dmrg.nsite, ifslc=True)
mpo_dmrg_init.genHops(dmrg, fmps, fmps, fnamel, 'L')
if dmrg.ifpt and dmrg.ifH0: dmrg.fdopXfhop()
#--------------------------------------------------------
# Initialization-0: normal initialization (lrpop)
# Renormalized operators for <L|P|L>.
#--------------------------------------------------------
if rank == 0 and dmrg.ifs2proj:
fnamelp = dmrg.path + '/lpop'
fnamerp = dmrg.path + '/rpop'
mpo_dmrg_init.genBops(dmrg,
fnamerp,
dmrg.npts,
dmrg.nsite,
ifslc=False)
mpo_dmrg_init.genPops(dmrg, fmps, fmps, fnamelp, 'L')
#--------------------------------------------------------
if dmrg.ifpt: dmrg.ifex = True
dmrg.nref = len(dmrg.wfex)
# 2016.09.13: By default, all MPS in wfex is in left canonical form!
if len(dmrg.wfex_canon) == 0: dmrg.wfex_canon = [True] * dmrg.nref
fbra = fmps
#--------------------------------------------------------
# Initialization-1: initialization (lrsop/lrpop)
# Excited states: Only rank-0 compute overlaps
#--------------------------------------------------------
if rank == 0 and dmrg.ifex:
for iref in range(dmrg.nref):
print '\n ### Ovlps: iref =', iref, ' rank =', rank, '###'
fket = dmrg.wfex[iref]
# <A|B>
if not dmrg.ifs2proj:
fnamel = dmrg.path + '/ref' + str(iref) + '_lsop'
fnamer = dmrg.path + '/ref' + str(iref) + '_rsop'
mpo_dmrg_init.genBmat(dmrg, fnamer, dmrg.nsite)
mpo_dmrg_init.genSops(dmrg, fbra, fket, fnamel, 'L')
# <A|P|B>
else:
fnamelp = dmrg.path + '/ref' + str(iref) + '_lpop'
fnamerp = dmrg.path + '/ref' + str(iref) + '_rpop'
mpo_dmrg_init.genBops(dmrg,
fnamerp,
dmrg.npts,
dmrg.nsite,
ifslc=False)
mpo_dmrg_init.genPops(dmrg, fbra, fket, fnamelp, 'L')
#--------------------------------------------------------
# RHS of PT equation: <fmps|H|MPS[i]>
if dmrg.ifpt:
# Generate E0
initE0pt(dmrg, fmps)
#--------------------------------------------------------
# Initialization-2: initialization (lrhop)
# Blocks for <Psi|H|Psi[i]>
#--------------------------------------------------------
ln = '#' * 10
for iref in range(dmrg.nref):
print '\n' + ln + ' <Psi|H|Psi[i]>: iref =', iref, ' rank=', rank, ln
fket = dmrg.wfex[iref]
# <A|H|B>
fnamel = dmrg.path + '/ref' + str(iref) + '_lhop'
fnamer = dmrg.path + '/ref' + str(iref) + '_rhop'
mpo_dmrg_init.genBops(dmrg,
fnamer,
dmrg.nops,
dmrg.nsite,
ifslc=True)
mpo_dmrg_init.genHops(dmrg, fbra, fket, fnamel, 'L')
#--------------------------------------------------------
# Initialization-3: initialization (lrdop)
# Blocks for <Psi|H0|Psi[i]>
#--------------------------------------------------------
if dmrg.ifH0:
dmrg.fdopXfhop()
for iref in range(dmrg.nref):
print '\n' + ln + ' <Psi|H0|Psi[i]>: iref =', iref, ' rank=', rank, ln
fket = dmrg.wfex[iref]
# <A|H|B>
fnamel = dmrg.path + '/ref' + str(iref) + '_ldop'
fnamer = dmrg.path + '/ref' + str(iref) + '_rdop'
mpo_dmrg_init.genBops(dmrg,
fnamer,
dmrg.nops,
dmrg.nsite,
ifslc=True)
mpo_dmrg_init.genHops(dmrg, fbra, fket, fnamel, 'L')
dmrg.fdopXfhop()
#--------------------------------------------------------
return 0