In QUICK v21.03, the two-electron repulsion integrals (ERI), exchange correlation (XC) energy, XC potential and their nuclear gradients are computed on the GPU. One-electron integrals (OEI) and their gradients are computed asynchronously on the CPU. This is the version that is distributed with free and open-source AmberTools v21. The underlying algorithm for computing OEI, ERI and their gradients is based on the recurrence relations scheme developed by Obara-Saika, Head-Gordon and Pople (OSHGP). The MM terms are handled by the Sander MD engine in AmberTools.