Several molecules are selected based on their intra-inter-molecular interaction representativity and atomic configuration complexity to benchmark the accuracy and performance of the mixed-precision DMRG scheme. The detailed information of the testing systems and the energy accuracy benchmark results of these systems are presented in Table . In this test, we benchmarked the mixedprecision scheme we presented in this article and compared with the original double-precision DMRG method which is implemented in the Kylin software. We also checked the energy result of the full single-precision DMRG method (i.e. all sweeps were calculated with the single-precision sweep method). The mixed-precision DMRG scheme shows good agreement with the double-precision result, thus the mixed-precision calculated energy deviates from double-precision for less than 0.01 kcal/mol. However, for most cases, the full single-precision DMRG may not deliver good result, especially for systems with complex orbital configuration like for the Cr 2 molecule. In fact, when transition metal elements are involved, the diagonalization and the DMRG sweep are harder to converge, which may affect the effectiveness and the performance of the mixed-precision scheme. This issue will be further investigated and discussed later. Generally speaking, the accuracy of the mixed-precision scheme will increase with the growth of m, which is the bond dimension of the MPS. As shown in the Fig. , when the bond dimension is larger than 1500, the error of the mixed-precision scheme is under 0.001 kcal/mol. %RQGGLPHQVLRQ $EVROXWHHUURU>×10 3 NFDOPRO@ 10 3 NFDOPRO Figure : Energy error (×10 -3 kcal/mol) of mixed-precision DMRG to double-precision DMRG for different bond dimensions. Benzene as benchmark system using the 6-31G basis set with a space of (24e,24o).