Fix numpy.exp overflow in smearing function
Fix numpy.exp overflow in smearing function

sunqm/pyscf,gkc1000/pyscf,gkc1000/pyscf,sunqm/pyscf,gkc1000/pyscf,gkc1000/pyscf,sunqm/pyscf,sunqm/pyscf,gkc1000/pyscf