add error handling for Negative overlap matrix eigenvalue.
add error handling for Negative overlap matrix eigenvalue.

materialsproject/custodian,davidwaroquiers/custodian,xhqu1981/custodian,specter119/custodian,specter119/custodian,specter119/custodian,materialsproject/custodian,materialsproject/custodian,alberthxf/custodian