CASINO manual - Theory of Condensed Matter

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• ‘DET 1 2 PL 6 3’ means ‘add an electron of spin 2 (down) to determinant 1, band 6, k-point 3’. • ‘DET 1 2 MI 6 3’ means ‘remove an electron of spin 2 (down) in determinant 1 from band 6, k-point 3’. • For nonperiodic systems, the k-point indices should just be set to 1. • If one subtracts a spin-up electron then the value of the input parameter neu should be decreased accordingly. Likewise for spin-down electrons. Similarly if one adds an electron. A multideterminant expansion is specified by the keyword ‘MD’: START MDET Title MDET example: use a multideterminant expansion. Multideterminant/excitation specification (see manual) MD 3 1.d0 1 0 0.5d0 2 1 0.5d0 2 1 DET 2 1 PR 4 5 6 7 DET 3 2 PR 4 5 6 7 END MDET Notes: • The ‘3’ in the line after ‘MD’ specifies that there are three determinants in the expansion. • The next three lines contain the determinant expansion coefficients for the three determinants (1, 0.5 and 0.5). Each expansion coefficient is followed by a ‘label’ and then an ‘optimizable’ flag. • The ‘optimizable’ flag must be 0 or 1, specifying that the expansion coefficient is fixed or free to be optimized. • All coefficients with the same label must have the same ‘optimizable’ flag. The ratios of these coefficients will be fixed during the optimization. There is therefore only one optimizable parameter in the example above, since the coefficients of the second and third determinants are constrained to be equal. • At least one determinant expansion coefficient must be fixed. • The excitation specifications are of the same form as for the ‘SD’ case. For example, ‘DET 2 1 PR 4 5 6 7’ means ‘in determinant 2 promote an electron of spin 1 (up) from band 4, k-point 5 to band 6, k-point 7’. Multideterminant expansions and excitations as described above are fully functional for Gaussian (gwfn.data), plane-wave (pwfn.data) and blip (bwfn.data) orbitals. They may also be used with numerical atomic (awfn.data) orbitals, although the excitation information must also be supplied in the awfn.data file (see Sec. 7.8.4). If blip or plane-wave orbitals are used then the user may specify a phase angle for a particular band and k point and a particular determinant and spin using ORB_PHASE where the phase angle is given in radians. The phase angle is used in the construction of a real orbital when the band is occupied at k but not −k, as described in Sec. 15. Specifying a phase has no effect when the band is occupied at both k and −k, or when the band is unoccupied at k. If one is studying a HEG and a complex wave function is used (i.e., complex wf = T) then the orbitals in the Slater determinants are of the form exp(ik · r), where the {k} are simulation-cell reciprocal-lattice points offset by the constant k offset vector specified in the free particles block in the input file. Before the occupancy of the plane-wave orbitals is worked out, the k vectors are sorted into increasing order of azimuthal angle φ k (innermost), then polar angle θ k , then magnitude 66
|k| (outermost). Hence one can specify excitations of electrons unambiguously. An example of the labelling of the {k} for a 2D HEG is shown below. Note that adding and subtracting electrons to or from particular states in a HEG is achieved by increasing or decreasing the electron number and making appropriate promotions. Note also that the angular sorting of the k vectors is not performed when the wave function is real, i.e., when complex wf = F. 52 47 51 40 32 27 31 39 41 23 16 11 15 22 38 53 33 17 7 3 6 14 30 50 48 28 12 4 1 2 10 26 46 54 34 18 8 5 9 21 37 57 42 24 19 13 20 25 45 43 35 29 36 44 55 49 56 The labelling of the k-vectors in a 2D HEG with a square cell. The filled points indicate the doubly occupied states in a 74-electron paramagnetic ground state. If one wishes to create an excitation of an up-spin electron from state 25 to state 47 in determinant 1, say, then one should include ‘DET 1 1 PR 1 25 1 47’ in the excitation specification in the MDET block in correlation.data. 7.4.5 Atomic orbital modification functions The format of the data set used to specify atomic orbital modifications in correlation.data is as follows: START ORBMODS Title Orbital modification functions for 2s and 2p orbitals of neon Spin-dependence (0->u=d; 1->u/=d) 0 Number of modification functions 2 START MODFN 1 Quantum numbers n and l 2 0 Expansion order 3 Parameters in modification function ; Optimizable (0=NO; 1=YES) END MODFN 1 START MODFN 2 Quantum numbers n and l 2 1 Expansion order 4 Parameters in modification function ; Optimizable (0=NO; 1=YES) END MODFN 2 END ORBMODS Notes: • Atomic orbital modification functions can only be used if atom basis type=‘numerical’ (i.e., numerical atomic orbitals are used) and the use orbmods keyword is set to T. When atom basis type=‘numerical’, the system consists of a single, isolated atom, with the nucleus lying at the origin. 67
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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
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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
Page 31 and 32: many cores, time limits etc, which
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 and 70: cusp conditions; otherwise, only th
Page 71: Detailed information about each of
Page 75 and 76: large and the wave function is near
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
Page 87 and 88: 1.3813695578425E+00 1.3957621401173
Page 89 and 90: PWSCF Method: DFT DFT Functional: u
Page 91 and 92: 0.125203784849961E-01 0.13042462855
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
Page 105 and 106: total weight must always be include
Page 107 and 108: The exporter does not currently wor
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
Page 119 and 120: not the case the defaults can be ch
Page 121 and 122: 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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