Fast Algorithms for FCI excited states
数学专题报告
报告题目(Title)：Fast Algorithms for FCI excited states
报告人(Speaker)：李颖洲（复旦大学）
地点(Place)：后主楼1124
时间(Time)：2023年9月26日（周二）16:00-17:00
邀请人(Inviter)：陈华杰
报告摘要
An efficient excited state method, named xCDFCI, in the configuration interaction framework, is proposed. xCDFCI extends the unconstrained nonconvex optimization problem in CDFCI to a multicolumn version, for low-lying excited states computation. The optimization problem is addressed via a tailored coordinate descent method. In each iteration, a determinant is selected based on an approximated gradient, and coefficients of all states associated with the selected determinant are updated. A deterministic compression is applied to limit memory usage. We test xCDFCI applied to H2O and N2 molecules under the cc-pVDZ basis set. For both systems, five low-lying excited states in the same symmetry sector are calculated together with the ground state. xCDFCI also produces accurate binding curves of carbon dimer in the cc-pVDZ basis with 10−2 mHa accuracy, where the ground state and four excited states in the same symmetry sector are benchmarked.
