Computational cost, limitations, known edge cases.

Briefly describe the role of exchange-correlation functionals in DFT, prior version xc.v8.6 , motivation for v8.7.1 .

This paper presents xc.v8.7.1 , a revised implementation of the exchange-correlation functional framework targeting improved accuracy for transition metal complexes and weak interactions. We detail modifications to the semi-local correlation component, benchmark against the GMTKN55 database, and report a mean absolute deviation reduction of 12% compared to xc.v8.6 . The code interface and numerical stability are also discussed.