TOMBO Ver.2 Manual

3.2 INPUT.inp 26
3.1.1 rct
"XX_rct" is the radius of the non-overlapping atomic sphere (“rct”) of XX atom in units
of [Å]. Here, note that user should write S _rct = 0.8 to define “rct” of S atom, for example,
because the atomic symbols H, B, C, N, O, F, S, K, V, Y, and I are one character only,
one blank is necessary between the atomic symbol and _. The sum of two “rct” values of
adjacent atoms should not exceed the interatomic distance. The value of “rct” may strongly
affect the one-shot GW calculation results. In such a case, “rct” should be chosen as small
as possible, although the necessary cut-off energy for plane waves is increased.
3.1.2 nc
"XX_nc" is the number of core AOs for which no truncation is performed. One should
write N _nc = 1 [default] to define “nc” of N atom (1s only), for example. For titanium, the
core orbitals of Ti are 1s 2 2s 2 2p 6 , so that there are 3 core AOs: 1s, 2s and 2p; so Ti_nc = 3.
3.1.3 nv
"XX_nv" is the number of valence AOs for which truncation (to confine inside the atomic
sphere) is performed. One should write N _nv = 2 [default] to define “nv” of N atom (2s
and 2p), for example. For titanium, the valene orbitals of Ti are 3s 2 3p 6 3d 2 4s 2 , so that there
are 4 valence AOs: 3s, 3p, 3d and 4s; so Ti_nv = 4.
3.1.4 ns
"XX_ns" is the number of s-type AOs for XX atom. One should write N _ns = 2 [default]
to define “ns” of N atom (1s and 2s), for example. For titanium, 1s 2 2s 2 2p 6 3s 2 3p 6 AOs are
used because 4s is quite extended. Therefore there are 3 s AOs: 1s, 2s and 3s; so Ti_ns = 3.
3.1.5 np
"XX_np" is the number of p-type AOs for XX atom. One should write N _np =
1 [default] to define “np” of N atom (2p), for example. For titanium, AOs of Ti are
1s 2 2s 2 2p 6 3s 2 3p 6 , so that there are 2 kinds of p orbits: 2p and 3p; so Ti_np = 2.
3.2 INPUT.inp
A typical form of INPUT.inp is shown in Table 3.3. # and mean comments.