CASINO manual - Theory of Condensed Matter

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7.4.3 Backflow parameters The parameters in the backflow functions are supplied to casino in a data set in the correlation.data file. The format is analogous to that of the Jastrow-factor data set. Please see the notes in Sec. 7.4.2 for information on the ‘truncation order’, ‘spin dependence’, etc. START BACKFLOW Title AE Carbon atom - empty parameter set Truncation order 3 START ETA TERM Expansion order 8 Spin dep (0->uu=dd=ud; 1->uu=dd/=ud; 2->uu/=dd/=ud) 1 Cutoff radii ; Optimizable (0=NO; 1=YES; 2=YES BUT NO SPIN-DEP) 0.d0 1 Parameter ; Optimizable (0=NO; 1=YES) END ETA TERM START MU TERM Number of sets; labelling (1->atom in s cell; 2->atom in p cell; 3->species) 1 2 START SET 1 Number of atoms in set 1 Labels of the atoms in this set 1 Type of e-N cusp conditions (0->PP/cuspless AE; 1->AE with cusp) 1 Expansion order 6 Spin dep (0->u=d; 1->u/=d) 1 Cutoff (a.u.) ; Optimizable (0=NO; 1=YES) 4.5 1 Parameter values ; Optimizable (0=NO; 1=YES) END SET 1 END MU TERM START PHI TERM Number of sets; labelling (1->atom in s cell; 2->atom in p cell; 3->species) 1 2 START SET 1 Number of atoms in set 1 Labels of the atoms in this set 1 Type of e-N cusp conditions (0=PP; 1=AE) 1 Apply no-curl constraint (0=NO; 1=YES) 1 Electron-nucleus expansion order N_eN 3 Electron-electron expansion order N_ee 3 Spin dep (0->uu=dd=ud; 1->uu=dd/=ud; 2->uu/=dd/=ud) 0 Cutoff (a.u.) ; Optimizable (0=NO; 1=YES) 0.d0 1 Parameter values ; Optimizable (0=NO; 1=YES) END SET 1 END PHI TERM START AE CUTOFFS Nucleus ; Set ; Cutoff length ; Optimizable (0=NO; 1=YES) END AE CUTOFFS END BACKFLOW 64
Detailed information about each of the backflow functions can be found in Sec. 23. Notes: • The polynomial form of η requires the specification of an expansion order as shown above. The two lines have to be removed when using any of the other two forms. • The η function has separate cutoff lengths for each of the spin-dependencies. The first one must be specified; every cutoff length not listed is initially set to the value of the first one. Set the ‘Optimizable’ flag to 2 to constrain all cutoff lengths to be the same during optimization too. • ‘Type of e-N cusp conditions’ in µ and Φ is used to specify whether to regard the atoms in the set as all-electron (AE) or pseudo-atoms (PP). PP cusp conditions are less restrictive than AE ones. The user should set this flag to 0 only if a pseudopotential is being used for the atom in question. • ‘Apply no-curl constraint’ in Φ is used to reduce the number of parameters in Φ and Θ when this number is too large for optimization to succeed. In principle, this flag should always be set to zero for the best results. • It is recommended that vm filter be set to T in the input file when optimizing backflow parameters using unreweighted variance minimization. • The AE CUTOFFS section will appear automatically in systems with all-electron atoms, and all cutoffs will be flagged as optimizable by default. 7.4.4 Excitations and multideterminant-expansion coefficients The xwfn.data file contains data that define the orbitals produced by the wave-function generating code. The file also specifies a reference configuration (the form of the Slater wave function), which may consist of one or more determinants. The ‘MDET’ block in the correlation.data file allows one either to use the reference configuration or to specify excitations, additions or subtractions from the reference configuration. Furthermore, it enables the user to construct an expansion in several determinants with optimizable expansion coefficients. The MDET block consists of a title followed by an arbitrary number of lines (up to ‘END MDET’), which contain tokens used to specify the excitations and the multideterminant configuration. The simplest case is when we want to use exactly the reference configuration specified in xwfn.data (this is the default behaviour if no MDET block is supplied). In this case, the single token ‘GS’ is used: START MDET Title MDET example: use reference configuration in xwfn.data file. Multideterminant/excitation specification (see manual) GS END MDET Promotions, additions and subtractions of electrons are specified using the keywords ‘PR’, ‘PL’ and ‘MI’, respectively. Several changes to the reference configuration can be made at once. Here is an example of a single-determinant (‘SD’) excited-state calculation: START MDET Title MDET example: use a single-determinant excited state. Multideterminant/excitation specification (see manual) SD DET 1 2 PR 3 4 5 6 DET 1 2 PL 6 3 DET 1 2 MI 6 3 END MDET Notes: • ‘DET 1 2 PR 3 4 5 6’ means ‘in determinant 1, spin 2 (down), promote an electron from band 3, k-point 4, to band 5, k-point 6’. 65
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CASINO User’s Guide Version 2.13
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8.6 GAUSSIAN94/98/03/09 . . . . . .
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29.2 Fourier transformation of CASI
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1 Introduction casino is a computer
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3.2 Legal stuff casino is given awa
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- Grossman-Mitas DMC-DFT molecular
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Your defined setup can then be perm
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- : perform compilation (default).
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6 Introductory user’s guide: how
Page 19 and 20: ATOM BASIS TYPE The basis used to r
Page 21 and 22: ENVMC v0.60: Script to extract VMC
Page 23 and 24: Std. err. in the mean DMC energy (a
Page 25 and 26: Jastrow factor from each cycle of t
Page 27 and 28: V(x) Ψ init (x) τ{ t Ψ 0 (x) x T
Page 29 and 30: the energy becomes roughly constant
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Page 33 and 34: Set the verbosity level of the mach
Page 35 and 36: 6.7 How to run coupled DFT-DMC mole
Page 37 and 38: unqmcmd --startqmc=M Start the chai
Page 39 and 40: config.out This is the name under w
Page 41 and 42: ‘slater-type’: use Slater-type
Page 43 and 44: CUSTOM SPAIR DEP (Block) This input
Page 45 and 46: initial configurations come from DM
Page 47 and 48: DTDMC (Real) Time step for DMC run
Page 49 and 50: FORCES INFO (Integer) Controls the
Page 51 and 52: nucleus is assumed to lie at the or
Page 53 and 54: MOVIECELLS (Logical) If F then casi
Page 55 and 56: OPT MAXITER (Integer) Largest permi
Page 57 and 58: of G vectors and discards all those
Page 59 and 60: half a million cores, it may be des
Page 61 and 62: VM REWEIGHT (Logical) If vm reweigh
Page 63 and 64: default this is 0 hartree. It shoul
Page 65 and 66: A very detailed specification of th
Page 67 and 68: -1 0 0 1 1 1 1 1 1 1 0 2 1 0 1 2 Pa
Page 69: cusp conditions; otherwise, only th
Page 73 and 74: |k| (outermost). Hence one can spec
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Page 77 and 78: R(i) in atomic units 0.000000000000
Page 79 and 80: 2. The charge-density Fourier coeff
Page 81 and 82: c_767: [ 996 ] ... Compressed expan
Page 83 and 84: valence charges for each atom %%%%%
Page 85 and 86: 1988). This can be found online. An
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Page 89 and 90: PWSCF Method: DFT DFT Functional: u
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Page 93 and 94: 3.3000000000000E+00 2.0000000000000
Page 95 and 96: Potential Number of grid points 200
Page 97 and 98: 9. Clearly, the total number of pos
Page 99 and 100: EBEST (DMC only) Best estimate of t
Page 101 and 102: Use G-vector set 1 Number of sets 2
Page 103 and 104: 1000.0 rho_a(G)*rho_b(-G) 16.0 4.12
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Page 109 and 110: 8.4.2 Generating gwfn.data files wi
Page 111 and 112: After successfully running properti
Page 113 and 114: % mv Test.FChk dna.Fchk run gaussia
Page 115 and 116: • By default, gaussian uses spin
Page 117 and 118: Routine Purpose qmc write Writes th
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8.10 TURBOMOLE Website: www.turbomo
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• crysgen06/09, crystaltoqmc: The
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• quickblock: Simple reblocking u
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• In Movie Settings choose Trajec
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the move rejection probability is h
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This leads to the single-electron d
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In the UNR [19] scheme the modified
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13.7 Evaluating expectation values
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Population-control catastrophes sho
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where u k has the periodicity of th
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Although the constraint equations a
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18 Wave-function updating Consider
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19.2 Evaluating the nonlocal pseudo
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of a unit point charge at r j in ev
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19.4.3 1D Coulomb interaction Coulo
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To investigate whether the extrapol
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correlations, such as might be enco
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where n is the order of the expansi
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terms by definition, and it can be
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which is therefore independent of r
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where the local energy, E L , is E
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Another variant of variance minimiz
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The energy minimization method used
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valid. The first problem, which ari
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• Is emin min energy too high? Th
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It may be activated by setting vmc
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that the number of configuration mo
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• It is possible to use blip orbi
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0.5 0.5 0.0 particle 1 det 1 : 9 or
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The clearup twistav script can be u
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In the infinite system limit, the s
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Note that this has the k −2 diver
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• The effective time step, Eq. (3
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1 2 H He 1.00794 4.00260 3 4 5 6 7
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and the Dirac delta function is δ(
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33.2.2 Atomic densities K eywords:
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The spin-density matrix is a two-by
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33.3.3 Homogeneous and isotropic sy
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33.4 Structure factor and spherical
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33.5 One-body density matrix, two-b
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[ where the approximation ρ (1)T
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The figure shows the localization l
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with F HFT mix = − F P mix = −
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The input keyword to activate the c
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To each walker r j , we assign a li
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37 Magnetic fields and the fixed-ph
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38 Analysis of the performance of C
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the orbitals, α = 2 [11]. The use
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39.2 Implementation basics and perf
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• Use ‘endif’ and ‘enddo’
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• Evidence of testing on serial a
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B Appendix 2: Automatic testing of
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• Delete any eepot.data and densi
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* "Generic" CASINO_ARCHs are intend
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- ‘head -n 1 /etc/redhat-release
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for a single job in an ensemble of
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inary executable. CASINO does not r
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otherwise. The following tags are o
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[2] V.R. Saunders, R. Dovesi, C. Ro
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[50] W. Janke, Statistical Analysis
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CASINO manual - Theory of Condensed Matter

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