def is_equivalent_cluster(site0,site1,comp0,comp1,lattice):
"""Check if two pairs of sites are equivalent
and if the sites are swapped.
:site0: Site
:site1: Site
:comp0: Site
:comp1: Site
:returns: bool,bool
"""
swithin0,swithin1=structure.bring_cluster_within(site0,site1,lattice)
cwithin0,cwithin1=structure.bring_cluster_within(comp0,comp1,lattice)
sitedelta,sitemap=structure.site_delta(swithin0,swithin1)
compdelta,compmap=structure.site_delta(cwithin0,cwithin1)
goodmap=False
mapswitch=False
if np.allclose(sitedelta,compdelta):
goodmap=True
#if the deltas have opposite signs, the sites map by translation, but they switched places
elif np.allclose(-sitedelta,compdelta) and sitemap and compmap:
goodmap=True
mapswitch=True
return goodmap,mapswitch
def dynamical_exp_inputs(site0,site1,lattice):
"""Determine rn, tb0 and tb1 needed
for the exponential term of the dynamical
matrix calculations for the given cluster.
Pivot always goes as first site.
:site0: Site
:site1: Site
:lattice: 2x2 matrix with a and b vectors as columns
:returns: (2x1 vector,2x1 vector, 2x1 vector)
"""
sw0=site0.bring_within(lattice)
sw1=site1.bring_within(lattice)
rn,_=structure.site_delta(site0,site1)
##Erm... not sure which one the real rn is...
#l0,_=structure.site_delta(sw0,site0)
#l1,_=structure.site_delta(sw1,site1)
#rn=l1-l0
tb0=structure.bring_within(site0._coord,lattice)
tb1=structure.bring_within(site1._coord,lattice)
return rn,tb0,tb1
