Re: oxygen atom's optimized PAO similar to 631++G** of GTO codes ( No.1 ) 
 Date: 2018/02/19 14:52
 Name: Reza
 Sorry, These are exponents and coefficients:
**** O 0 S 6 1.00 5484.6717000 0.0018311 825.2349500 0.0139501 188.0469600 0.0684451 52.9645000 0.2327143 16.8975700 0.4701930 5.7996353 0.3585209 SP 3 1.00 15.5396160 0.1107775 0.0708743 3.5999336 0.1480263 0.3397528 1.0137618 1.1307670 0.7271586 SP 1 1.00 0.2700058 1.0000000 1.0000000 SP 1 1.00 0.0845000 1.0000000 1.0000000 D 1 1.00 0.8000000 1.0000000 ****

Re: oxygen atom's optimized PAO similar to 631++G** of GTO codes ( No.2 ) 
 Date: 2018/02/23 18:51
 Name: T. Ozaki
 Hi,
631G** may correspond to
H7.0s2p1 O7.0s2p2d1
and 631++G** may correspond to
H7.0s2p2d1 O7.0s3p2d1f1
while I am not sure which angular momentum is augmented by the diffuse functions ++.
Regards,
TO

Re: oxygen atom's optimized PAO similar to 631++G** of GTO codes ( No.3 ) 
 Date: 2018/04/01 00:53
 Name: Reza
 Hi Prof. Ozaki
In 631G, the valance electron should be defined by two sets of contracted GTOs. The first contracted GTO is defined by using 3 GTO, and the second contracted one is defined by 1 GTO (31G in 631G). Please note that the 6 in 631G is for core electron which is not considered in OPENMX. So, I think I should use following one for Oxygen atom:
for 631G: O7.0s4p4 for 631G**: O7.0s4p4d1 for 631++G**: O7.0s5p5d1
+ means diffused orbitals with principal quantum number of n+1. The first + is for oxygen, and the second one is for H atom. * means polarized orbital with L+1.
I will thank, if you leave me any comment in this field.
Very Thanks. Reza

Re: oxygen atom's optimized PAO similar to 631++G** of GTO codes ( No.4 ) 
 Date: 2018/04/01 07:29
 Name: T. Ozaki
 Hi,
Since the basis functions provided in OpenMX are defined numerically and optimized variationally, the corresponding basis set for 631G should be O7.0s2p2 rather than O7.0s4p4. The others should be changed accordingly.
Regards,
TO

Re: oxygen atom's optimized PAO similar to 631++G** of GTO codes ( No.5 ) 
 Date: 2018/04/02 02:08
 Name: Reza
 So, If I correctly understand, you mean that each contracted GTO should be replaced by only one APO. Right?
For example, 641G will be translated to O7.0s2p2 similar to 631G, and 6311G to O7.0s3p3. Am I right?

Re: oxygen atom's optimized PAO similar to 631++G** of GTO codes ( No.6 ) 
 Date: 2018/04/02 08:37
 Name: T. Ozaki
 Hi,
The contraction means that an optimized basis orbital is expressed by a linear combination of primitive orbitals (Gaussian functions for your case), and the contraction coefficients are predetermined so as to reproduce some a reference function such as atomic orbital. In OpenMX, the optimized orbitals are generated in a similar way. An important difference between them is that one uses analytic functions, the other numerically defined functions for the primitive basis functions. It should be noted that after the contraction the opimized orbital returns to a single numerical table for the numerical functions, while all the primitive functions have to be treated explicitly for the analytic functions when matrix elements are evaluated.
Regards,
TO
