c_ratio = 0.0
run_begin(calc_variables())
for blk in range(1, nblock + 1): # Loop over blocks
blk_begin()
for stp in range(nstep): # Loop over steps
r_moves = 0
c_moves = 0
for i in range(n): # Loop over atoms
# Centre of mass move
dc = random_translate_vector(dc_max / box,
np.zeros(3, dtype=np.float_))
partial_old = PotentialType(0.0, 0.0, False)
partial_new = PotentialType(0.0, 0.0, False)
for k in range(p): # Loop over ring polymer indices
rkj = np.delete(r[k, :, :], i,
0) # Array of all other atoms for this k
partial_old = partial_old + potential_1(
r[k, i, :], box, r_cut, rkj,
p) # Old atom classical potential etc
rki = r[k, i, :] + dc
rki = rki - np.rint(rki)
partial_new = partial_new + potential_1(
rki, box, r_cut, rkj,
p) # New atom classical potential etc
assert not partial_old.ovr, 'Overlap in current configuration'
if not partial_new.ovr: # Test for non-overlapping configuration
ntry = n # Each step consists of ntry tries (during which N might vary)
for itry in range(ntry):
zeta = np.random.rand() # Uniform random number in range (0,1)
if zeta < prob_move:
m_try = m_try + 1
i = np.random.randint(n) # Choose moving particle at random
rj = np.delete(r, i, 0) # Array of all the other atoms
partial_old = potential_1(r[i, :], box, r_cut,
rj) # Old atom potential, virial etc
assert not partial_old.ovr, 'Overlap in current configuration'
ri = random_translate_vector(
dr_max / box,
r[i, :]) # Trial move to new position (in box=1 units)
ri = ri - np.rint(ri) # Periodic boundary correction
partial_new = potential_1(ri, box, r_cut,
rj) # New atom potential, virial etc
if not partial_new.ovr: # Test for non-overlapping configuration
delta = partial_new.pot - partial_old.pot # Use cut (but not shifted) potential
delta = delta / temperature
if metropolis(delta): # Accept Metropolis test
total = total + partial_new - partial_old # Update total values
r[i, :] = ri # Update position
m_acc = m_acc + 1 # Increment move counter
elif zeta < prob_move + prob_create: # Try create