solveLocalM()

IterativeExit syten::MPS::DMRG::LBOWorker::solveLocalM

(

std::vector< Tensor< 4 > > &

trans_ops

)

Solve the local eigenvalue problem at the current position on the MPS tensor.

Pre-computes the (LW) contraction and then only multiplies in M and R on each Lanczos step. Also cf. 778cf4cd897b16c488dae4f920c0dc2950676187

Index ordering is optimal under the assumption that MPOs have [r=1,l=2,u=3,d=4] and MPSs have [l=2,u=1,r=3]

Optimal contraction sequence for d != 1

References std::vector< T >::begin(), std::vector< T >::end(), syten::MPS::lbo_lbo_mps_cmp(), std::move(), syten::orthogonalise_solve_svd(), std::vector< T >::push_back(), std::vector< T >::reserve(), std::vector< T >::size(), and SYTEN_ASSERT_DEBUG.

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