Tracked down and fixed bug using sanitizer
Tracked down and fixed bug using sanitizer

Changed
auto one = Eigen::Tensor<Scalar, 1>(Rdim).constant(1.0);
to
Eigen::Tensor<Scalar, 1> one = Eigen::Tensor<Scalar, 1>(Rdim).constant(1.0);

since using the former caused an error with memory addresses. This bug has been very difficult to catch and may have been causing
other UB errors that appeared randomly previously.


Former-commit-id: 9c793a4399b703e76417b5bfdd772806d839638b
DavidAce/DMRG,DavidAce/DMRG,DavidAce/DMRG,DavidAce/DMRG