1##
2## Real-time TDDFT QA
3## rt_tddft_dimer_charge
4##
5## This tests the fragment approach by computing the charge dynamics
6## in a H2 dimer (separated by 2A in the z-direction).  An extra
7## electron is added to one of the H2 molecules, each are converged to
8## their individual ground states, then the electron dynamics are
9## propagated from this extremely non-physical initial condition.  Of
10## course, this is not properly converged with basis set, etc, and is
11## just for testing purposes.
12##
13## Here, instead of the time-dependent dipole moment, we are
14## interested in the time-dependent charge on each H2 molecule, akin
15## to a TD Mulliken analysis.
16##
17## The excess electron will oscillate between the top and bottom H2
18## molecules.  Note that output "Charge" corresponds to total
19## electronic charge, i.e., neutral H2 has Charge = -2.0, whereas -1
20## H2 has Charge = -3.0.  The overall dimer has Charge = -5.0.
21##
22## To see the charge dynamics of the alpha (excess) electron:
23##
24## nw_rtparse -xcharge -salpha -gbottom frags.out > bottom.dat
25## nw_rtparse -xcharge -salpha -gtop frags.out > top.dat
26## gnuplot > plot "bottom.dat" w l, "top.dat" w l
27##
28## Suggested checks:
29##
30## nw_rtparse -xcharge -salpha -gtop -c myrun.out frags.out
31## nw_rtparse -xcharge -salpha -gbottom -c myrun.out frags.out
32## nw_rtparse -xdipole -salpha -gdimer -pz -c myrun.out frags.out
33## nw_rtparse -xdipole -sbeta -gdimer -pz -c myrun.out frags.out
34##
35
36title "Hydrogen dimer fragment charge dynamics"
37echo
38
39start frags
40
41geometry "bottom" units angstroms nocenter noautoz noautosym
42 H    -0.38 0.0 0.0
43 H     0.38 0.0 0.0
44end
45
46geometry "top" units angstroms nocenter noautoz noautosym
47 H    -0.38 0.0 2.0
48 H     0.38 0.0 2.0
49end
50
51geometry "dimer" units angstroms nocenter noautoz noautosym
52 H    -0.38 0.0 0.0
53 H     0.38 0.0 0.0
54 H    -0.38 0.0 2.0
55 H     0.38 0.0 2.0
56end
57
58basis
59  H library cc-pvdz
60end
61
62## universal dft settings
63dft
64  xc pbe0
65  odft
66end
67
68
69## -1 fragment
70charge -1
71set geometry "bottom"
72dft
73  mult 2
74  vectors input atomic output "bottom.movecs"
75end
76task dft energy
77
78
79## neutral fragment
80charge 0
81set geometry "top"
82dft
83  mult 1
84  vectors input atomic output "top.movecs"
85end
86task dft energy
87
88
89## assemble the two fragments but don't do SCF
90charge -1
91set geometry "dimer"
92dft
93  mult 2
94  vectors input fragment "bottom.movecs" "top.movecs" output "dimer.movecs"
95  noscf
96end
97task dft energy
98
99
100##
101## Do rt-tddft on this crazy initial condition. No need for excitation
102## since we are far from the ground state anyways.
103##
104rt_tddft
105  tmax 50.0
106  dt 0.2
107
108  nrestarts 0
109
110  print charge dipole energy
111
112  load vectors "dimer.movecs"
113end
114task dft rt_tddft
115
116