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arXiv · 1202.2957

Efficient computation of Hamiltonian matrix elements between non-orthogonal Slater determinants

Yutaka Utsuno·Noritaka Shimizu·Takaharu Otsuka·Takashi Abe
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Abstract

We present an efficient numerical method for computing Hamiltonian matrix elements between non-orthogonal Slater determinants, focusing on the most time-consuming component of the calculation that involves a sparse array. In the usual case where many matrix elements should be calculated, this computation can be transformed into a multiplication of dense matrices. It is demonstrated that the present method based on the matrix-matrix multiplication attains $\sim$80% of the theoretical peak performance measured on systems equipped with modern microprocessors, a factor of 5-10 better than the normal method using indirectly indexed arrays to treat a sparse array. The reason for such different performances is discussed from the viewpoint of memory access.

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Yutaka Utsuno, Noritaka Shimizu, Takaharu Otsuka, Takashi Abe. 2012-09-19. Efficient computation of Hamiltonian matrix elements between non-orthogonal Slater determinants. https://doi.org/10.1016/j.cpc.2012.09.002

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