The latest evaluated nuclear data libraries, including ENDF/B-VIII.0, TENDL2019, all have two formats, the Evaluated Nuclear Data File (ENDF-6) nuclear data format, and the Generalised Nuclear Database Structure (GNDS) format. The first official public documentation of all of the options for storing data in GNDS was released by the Working Party on International Nuclear Data Evaluation Cooperation (WPEC) of the Nuclear Energy Agency. The generalized derived class is designed to be compatible with ENDF-6 and GNDS in nuclear data processing code NECP-Atlas, and the GNDS-Toolkit is developed in NECP-Atlas to parse and convert GNDS. ACE format library and multi-group library are generated based on GNDS, and they are used in the Monte-Carlo code and deterministic based code to compare with ENDF-6. The numerical results show that GNDS libraries can be processed by NECP-Atlas competently to generate specific format library and the difference in ENDF-6 and GNDS is very small.