With sympy==1.5 kwant.qsymm.builder_to_model results in malformed BlochModel
With sympy=1.5
the BlochModel
returned by kwant.qsymm.builder_to_model
has momenta
as strings, while these should be sympy.Symbol
s. The reason is all(m in qsymm.model._commutative_momenta for m in ('k_x', 'k_y'))
(where _commutative_momenta
is a list of sympy.Symbol
s) evaluates to True in 1.5, it is False in all other versions I tried. We should require sympy==1.5.1
for example, or rewrite this check in some more failsafe way.
Edited by Dániel Varjas