Readme

Source code:
The source code is given in "Program source code.txt".

Because of limitation of Journal's file upload system, we renamed Visual Basic files (ProgramNonBorn.frm, ProgramNonBorn.vbp, ProgramNonBorn.vbw) to
"c4ra02422b2.txt", "c4ra02422b3.txt", and "c4ra02422b4.txt" temporarily. 
Prior to using these files in Visual Basic, change the names to original ones (i.e., "c4ra02422b2.txt" to "ProgramNonBorn.frm", "c4ra02422b3.txt" to "ProgramNonBorn.vbp", and "c4ra02422b4.txt" to "ProgramNonBorn.vbw").

Installation:
1)	Copy the three Visual Basic files (ProgramNonBorn.vbp, ProgramNonBorn.frm, ProgramNonBorn.vbw) to your computer.
2)	Using Visual Basic 6.0, open the files and compile them to an executable file.

Execution:
1)	Double-click the resulting executable file.
2)	Make a target Gaussian (optimization) logfile name appear in the "File list" box of the program window by clicking appropriate images in "Drive" and "Directory" boxes 
(i.e., Change the current folder using "Drive" and "Directory" box operations).
3)	Select the logfile name by clicking it in the "File list" box.
4)	Load the file by clicking the "File Load" button.
5)	Select "charge type" to use by clicking an appropriate "check-option" (circular) button
(Mulliken, MK, NPA, Hirshfeld, ChelpG, and AIM charges are available).
6)	If necessary, modify the van der Waals (vdW) surface by adding a modification length into the "Surface modification" box. 
For instant, adding 1.40 angstrom, the solvent-accessible surface (SAS) will be created.
7)	Calculate electric field strengths by clicking the "Execution" button. Then, you will get two files (*.txt and *.RES) in the current folder. 
"*.txt" gives a list of surface-points’ coordinates, electric field strengths (Ei), and minute surface areas (Si) at those points, 
while "*.RES" includes control variables for a multivariate regression analysis. 
Using the five calculation values listed at the last of the file and experimental hydration energies of ions, 
you can perform the multivariate analysis.