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SI2-SSI-1147794: Sustainable Development of Next-Generation Software in Quantum Chemistry C. David Sherrill 1 , Edmond Chow 2 , and T. Daniel Crawford 3 Acknowledgments Serial PANACHE Application: DF-CCSD(T) Interfaces to Quantum Chemistry Programs Overview We seek to deploy rank-reduction approximations for the electron repulsion integral tensor on massively-parallel hardware by developing an interface for the abstract manipulation of factor tensors distributed using sustainable third-party massively parallel APIs Overall Toolbox: LibPANACHE Density Fitting (DF) Electron-Repulsion Integral (ERI) Tensor: DF Factorization: Three-Index DF Integrals: Two-Index DF Integrals: Symmetric DF Factorization: 1 Center for Computational Molecular Science and Technology School of Chemistry and Biochemistry School of Computational Science and Engineering Georgia Institute of Technology 2 School of Computational Science and Engineering Georgia Institute of Technology 3 Department of Chemistry Virginia Polytechnic Institute and State University Auxiliary Basis Expansion: Interfaces Available: • C++ • Fortran Major Packages : • PSI4 • GAMESS (in progress) • Dalton (in progress) Specific Programs : • DFOCC: Orbital-optimized second-order many-body perturbation theory with DF and CD (Ugur Bozkaya, Ataturk University) • FNOCC: DF/CD CCSD(T) with GPU capabilities (Eugene DePrince, Florida State) • DF-SAPT: DF/CD Symmetry-adapted perturbation theory with natural orbital capabilities (Rob Parrish, Georgia Tech) • CCENERGY: (DF-)CCSD(T) energies, gradients, polarizabilities, excitation energies, chiroptical properties (Daniel Crawford, Virginia Tech) Conventional Approximate Serial Parallel Integrals Hardware Target Advantages : -Approximate integrals already provide substantial tractability gains in serial -Low-rank representations are easy to distribute in aggregate memory -Approximate integrals shift FLOP effort to efficient, easily parallelized linear algebra operations Solver CGSolver DLSolver DLXSolver JK PDirectJK DFJK DirectJK V RTDAV RKSV UKSV Uses Inherits HF TDHF CPHF CIS SAPT0 Client Codes LibFock LibFock Layout: Many-Body Problems: LibLowRank LibLowRank Layout: DF-ERI CD-ERI PS-ERI Client Codes TensorAPI DF-SAPT0 PANACHE Layer Serial/Parallel Interfaces SerialTensor GlobalArrays CTF Serial PANACHE Application: A-SAPT Parallel PANACHE Application: GTFock One-Body Problems: LibFock 2) Identify two key occupied bodies in each many-body interaction term. 1) Allow the many-body interaction to occur naturally (SAPT0 for now). 4) Visualize Results 3) Perform key two-body summations with local quasiparticles. A-SAPT Formalism: PANACHE Implementation: •>50 pages of complicated A-SAPT0 equations become 8200 lines of simple, readable code (less than our previous SAPT0 code!) •LibFock is used for electrostatics, exchange, induction •LibLowRank is used for dispersion and some auxiliary computations •Density fitting acceleration is automatically enabled by LibPANACHE •Resultant test code is already production-level, works for >220 atoms Application to Buckycatcher: Electrostatics: Exchange: Dispersion: R.M. Parrish and C.D. Sherrill, J. Chem. Phys. 141, 044115; J. Chem. Theory Comput. 10, 4417 (2014) A.E. DePrince III and C.D. Sherrill, J. Chem. Theory Comput., 9, 293 (2013) A.E. DePrince III and C.D. Sherrill, J. Chem. Theory Comput., 9, 2687 (2013) First Definitive Determination of 3-Body Contribution to the Lattice Energy of an Organic Crystal Errors of FNO-DF-CCSD(T) vs Conventional CCSD(T) for Intermolecular Interactions (S22 Test Set) DF/CD-FNO-CCSD(T) with T 1 -Transformation: Represent all ERIs via DF/CD Approximation: Work in a truncated natural orbital (FNO) virtual space: Use a T 1 -Transformed Hamiltonian to reduce complexity; CCSD equations then look like CCD Examination of Indinivir Binding to HIV-II Protease Using Truncated Models of Increasing Size Parallel Integral-Direct Generalized J and K Matrices: •2D tiling of shell pairs •Predetermination of near-optimal task assignments •Work-stealing construct for load-leveling •Designed to minimize communications •Built on GlobalArrays PArallel Numerical Algorithms in CHemistry Engine (PANACHE) Scheme: Tensor DF-CCSD(T) Laplace-Den THC-ERI TensorOps LibLowRank LibFock JK V Solver Uses Inherits Client Codes LibLowRank DF-ERI CD-ERI PS-ERI Laplace-Den THC-ERI DF-MP2 DF-(T) DF-ASAPT0 DF-CCSD THC-CCSD X NO transformation E. Chow, X. Liu, S. Misra, M. Dukhan, M. Smelyanskiy, J. R. Hammond, Y. Du, X.-K. Liao, and P. Dubey, Int. J. High Performance Comput. Appl., submitted E. Chow, X. Liu, M. Smelyanskiy, and J. R. Hammond, J. Chem. Phys., submitted Demonstration of Negligible Errors of FNO (cutoff 10 -5 ), Density Fitting, and Cholesky Decomposition Approximations, and their combinations •FNO-DF-CCSD(T) code allowed a resolution of the controversy over the size of 3-body contributions to the lattice energy of crystalline benzene [M. R. Kennedy et al., J. Chem. Phys. 140, 121104 (2014)] •3-body terms contribute 0.89 kcal/mol (7.2% of lattice energy) •3-body dispersion is only 0.76 kcal/mol, significantly smaller than some recent estimates •FNO-DF approach sped up trimer computations by ~4x (8.5 days to 2.1 days) 3.8 Å cutoff, 3555 bf 18.0 Å cutoff, 27394 bf, 879 TF/s Fock build on Tianhe-2 GTFock vs NWChem on Stampede (3.8 Å system)
