(Some of the) Quantum Chemical Advances in the Q- Chem 4.0 Program Package

Transcription

1 (Some of the) Quantum Chemical Advances in the Q- Chem 4.0 Program Package Yihan Shao Texas A&M Workshop October 26, 2012

2 Outline About Q- Chem A brief review of quantum chemistry models Twelve reasons to use Q- Chem

3 Milestones 1997: Q- Chem v1.0 first O(N) DFT code (made possible with CFMM) 1999: Prof. John Pople joined Q- Chem 2000: Q- Chem v : Spartan adopts Q- Chem as its back- end engine 2006: Q- Chem v : Q- Chem v4.0 March 2012, v4.0; October 2012, v4.0.1

4 Open teamware US developers Q- Chem (Pi+sburgh) Aspuru- Guzik (Harvard) Beran (UC Riverside) Dunietz (Kent State) Dutoi (U Pacific) Furlani (Buffalo) Gwaltney (MS State) Head- Gordon (Berkeley) Herbert (Ohio State) Lambrechet (U Pi^) King (Bethel) Krylov (USC) Rossolov (SC) Schaefer (U Georgia) Sherrill (Georgia Tech) Slipchenko (Purdue) Steele (Utah) Subotnik (U Penn) Truhlar (Minnesota) Van Voorhis (MIT) Woodcock (USF) Zimmerman (Michigan) Other developers Baer (Jerusalem) Besley (No`ngham) Casanova (Barcelona) Chai (Taipei) Dreuw (Heidelberg) Gill (ANU Canberra) Hsu (Taipei) Jung (KAIST) Klamt (Leverkusen) Liang (Xiamen) Ochsenfeld (Munich) Rhee (Postech) Rosta (London) Xu (Shanghai)

5 Outline About Q- Chem A brief review of quantum chemistry models Twelve reasons to use Q- Chem

6 Molecular orbital theory Molecular orbitals of H 2 O (plo^ed with IQmol) ψ 2 ψ 4 ψ 6 ψ 1 ψ 3 ψ 5 ψ 7

7 Electron density ψ 7 ψ 6 ψ 5 ψ 4 ψ 3 ψ 2 5! i=1!(r) = 2 " i (r) 2 Electron density ψ 1

8 Hartree- Fock and DFT Initial guess for MOs: ψ i Compute meanfield potential: Ψ i è f NO Orbital update: f è new Ψ i Converged? YES END

9 Hartree- Fock and DFT Components of mean- field potenhal Computed with linear- scaling O(N) algorithms in Q- Chem Core Hamiltonian (h): kinehc energy (T) + nuclear a^rachon (V) Coulomb potenhal (j) Hartree- Fock exchange (v X,HF ) Numerial exchange and numerical correlahon (v X, v C ) Hartree- Fock, h + j - v X,HF Pure DFT (BLYP, PBE, PW91), h + j - v X +v C Hybrid DFT (B3LYP, PBE0), h + j C X,HF v X,HF - (1- C X,HF )v X +v C C X,HF : 0.2 for B3LYP, 0.25 for PBE0

10 Correlahon methods Perturbahon methods Moller Plesset PT2 (MP2), O(N 5 ) Coupled cluster method CCSD, O(N 6 ) Full Configurahon interachon (FCI), exp(αn)

11 Computahonal method Electron correlaeon FCI CC DFT MP2 HF Higher Accuracy STO- 3G 6-31G* 6-31+G* cc- pvdz aug- cc- pvdz G** G(3df,3pd) cc- pvtz aug- cc- pvtz cc- pvqz aug- cc- pvqz Basis set

12 Benzene dimer

13 Outline About Q- Chem A brief review of quantum chemistry models Twelve reasons to use Q- Chem

14 Lutein (C 40 H 56 O 2 ) #1: Computahonal Efficiency Hartree- Fock, B3LYP, BLYP cc- pvdz basis set (50,194) grid for B3LYP and BLYP calculahons 1 Harpertown node, 2.5GHz, one processor (np=1)

15 Computahonal Efficiency Q- Chem Energy Another package Hartree- Fock B3LYP BLYP # SCF cycles Timing 1145 s 1604 s 625 s Energy #SCF cycles Timing 1718 s 2405 s 2010 s Q- Chem s HF and B3LYP calcns are 30-40% faster Q- Chem s BLYP calcns is 3 hmes faster

16 Twelve reasons #1: Efficient kernels for electron integrals and numerical integrahon Ground state #2: dispersion funchonals #3: perturbahon methods #4: energy decomposihon analysis Kinehcs, Dynamics #8: freezing string #9: spin- flip methods #10: ab ini\o dynamics Excited State #5: TDDFT grad and hess #6:range- separated fnls #7: charge/energy transfer Environment Effect #11. Solvahon #12. QM/MM

17 #2: Dispersion Funchonals empirical correchon D (Grimme) implemented by Ed Hohenstein, David Sherrill D3(Grimme) implemented by Jengda Chai s group D as in wb97x- D Jengda Chai and Marhn Head- Gordon XDM Axel Becke Zhenghng Gan, Emil Proynov, Jing Kong David Sherrill s group perturbahve correchon wb97x- 2 Jengda Chai and Marhn Head- Gordon XYG3, XYGJ- OS Xin Xu, Igor Zhang, Bill Goddard, Yousung Jung

18 #3: Perturbahon methods MP2, O(N 5 ) RI- MP2, O(N 5 ) Dual- basis RI- MP2, O(N 5 ) OS- MP2, O(N 4 ) OpenMP implementahon Adrian Mak and Marhn Head- Gordon GPU implementahon of RIMP2 Single precision Mixed- precision general matrix mulhply (MGEMM) Roberto Olivares- Amaya, Leslie Vogt, Mark Watson, Yihan Shao, Alan Aspuru- Guzik

19 Pertubahve methods Head- Gordon group Force. 6-31G** basis. Tight cutoffs (12/9) SOS- MP2 is faster for large systems. Advantage increases with size HF MP2 RIMP2 SOSMP2 (alanine) (alanine) (alanine)

20 Independently assess atomizahon energies 148 molecules from the G2 database Compare against CCSD(T) (cc- pvtz basis) SOS- MP2 is significantly be^er (and cheaper) than MP2 MP2 SOS- MP2 RMS dev Max dev

21 Long- range interachons Permanent electrostahcs Polarizahon (induchon) Van der Waals interachons Interachon energies Short- range interachons Pauli repulsion (filled orbital overlap) charge transfer (filled/empty overlap) Not uniquely defined, but a prachcal EDA needs to define/separate these terms

22 #4: Energy decomp analysis A Hartree- Fock or DFT interachon energy is decomposed as:!e =!E FRZ +!E POL +!E CT +!E HO FRZ: Interachon energy using frozen orbitals Permanent electrostahcs, exchange repulsion, (Van der Waals). POL: Polarizahon from ALMO- SCF Induchon effects treated fully self- consistently CT: Pairwise addihve donor- acceptor interachons Separates forward/back donahon HO: higher- order charge transfer from full SCF Not decomposable Khaliullin, Lochan, Cobar, Bell, Head- Gordon, 2007

23 L M donahon in W(CO) 6 ΔE(L M) = 101 kj/mol ΔQ(L M) = 0.04 e 1st complementary orbital pair: 98% of ΔE 97% of ΔQ Bold: donor orbital Faint: acceptor orbita Khaliullin and Head- Gordon

24 M L donahon in W(CO) 6 ΔE(M L) = 142 kj/mol ΔQ(M L) = 0.25 e 1st complementary orbital pair: 50% of ΔE 50% of ΔQ Bold: donor orbital Faint: acceptor orbital

25 Configurahon Interachon ψ 7 ψ 6 ψ 5 ψ 4 ψ 3 ψ 2 ψ 1 Hartree- Fock configuraeon CIS wavefunceon is a linear combinaeon of singly- excited configuraeons

26 #4: TDDFT grad and hess TDA and TDDFT analyhc gradient Cherri Hsu, Andreas Dreuw, Marhn Head- Gordon Fenglai Liu, Zhenghng Gan, Yihan Shao LDA, BLYP, B3LYP, PW91, ωb97, ωb97x, ωb97x- D LRC- ωpbepbe, LRC- ωpbehpbe, CAM- B3LYP TDDFT hessian Jie Liu and Wanzhen Liang LDA, BLYP, B3LYP

27 #5: Range- separated funchonals mainly for (charge- transfer) excited states ωb97, ωb97x, ωb97x- D Jengda Chai and Marhn Head- Gordon ωpbe, ωpbeh BNL John Herbert s group Roi Baer et al CAM- B3LYP Nick Handy et al (non Q- Chem developers)

28 Tryptophan excited state L a L b B3LYP: 4.91eV e 4.99eV 0.06e 5.19eV 0.37e 5.38eV 0.46e 5.82eV e L b L a ωb97x:5.30ev 0 e 5.47eV 0 e 5.52eV e 6.89eV e 7.14eV e

29 #7. charge/energy transfer Electron transfer Constrained DFT Qin Wu and Troy van Voorhis Direct coupling Wesley You and Cherri Hsu Excitahon energy transfer Fragment excitahon difference (FED) Wesley You and Cherri Hsu

30 #8: freezing string method R R Tangent Step Perpendicular Step(s) Repeat Grow a string to connect the reactant and product Behn, Zimmerman, Bell, Head- Gordon, 2011

31 #9: spin- flip methods a i a i a i reference a i SF- CIS, EOM- SF- CCSD (Krylov) SF- DFT (Krylov and Shao) RAS- nsf (Casanova, Rhee, Zimmerman, Head- Gordon) a i

32 #10: ab ini\o dynamics z- vector extrapolahon Ryan Steele MP2 and CIS/TDDFT Quasi- classical trajectory molecular dynamics Daniel Lambrecht and Marhn Head- Gordon Put zero- point energy into each normal mode during molecular dynamics Describe vibrahonal effects in MD simulahon

33 #11: solvahon Adrian Lange John Herbert Switch funchon Gaussian charges

34 #12: QM/MM Q- Chem/Charmm interface Energy/Gradient Woodcock, Hodoscek, Gilbert, Brooks, 2007 Hessian Ghysels, Woodcock, Shao, Brooks, 2010 Q- Chem internal QM/MM code First developed by Shao and Freindorf Improved by Lange and Herbert

35 More about Q- Chem Q- Chem 2.0: a high- performance ab ini&o electronic structure program package J. Kong, C. A. White, A. I Krylov and 33 other authors J. Comput. Chem. 16, 1352 (2000) Advances in methods and algorithms in a modern quantum chemistry program package Y. Shao, L. Fush- Molnar, Y. Jung, and 64 other authors Phys. Chem. Chem. Phys. 8, 3172 (2006)

36 How to reach us Sales (demo/permanent) chem.com chem.com chem.com Support chem.com iopenshell forum Facebook (h^p://

37 Acknowledgements Prof. Steven Wheeler, Texas A&M Q- Chem Colleagues Evgeny Epifanovskiy Zhenghng Gan MarySue Griffin Jing Kong Emil Proynov Former Colleagues Shawn Brown ChunMin Chang Marek Freindorf Laszlo Fush- Molnar All Q- Chem developers and users (including you!)

38 Schedule 10:00-10:40, Professor Steven Wheeler Opening Remarks and "Computa\onal Organic Chemistry: From Non- Covalent Interac\ons to Organocatalysis 10:40-11:20 Introduc\on to the Features of Q- Chem :20-12:20 Tutorial #1: Basic Q- Chem Calcula\ons using IQmol 12:20-1:00, Lunch Break 1:00-2:00 Tutorial #2: Studying Chemical Reac\ons with Q- Chem 2:00-3:30 Tutorial #3: "Advanced Topics: Energy Decomposi\on Analysis, Excited States, Solva\on and QM/MM 3:30-4:00, Dr. Marek Freindorf Combined QM/MM Calcula\ons of Ac\ve Sites in Heme Proteins