1. The TRUSTE optimizer has been updated with methods proposed by R. Lindh, Chem. Phys. Lett. 241, (1995) 423.
  2. The default optimizer has been changed from EF with a diagonal Hessian to EF with LINDH Hessian.
  3. SCFCRT can now be set to values smaller than 1.0D-11 in the input file.
  4. The SCF convergence tolerance has been adjusted in test runs 16n and 43 to give more consistent results across platforms.


  1. The SM5.0R surface tension parameters now include phosphorus for non-aqueous solvents.
  2. Several changes were made to the routines that read input and write output to make them more portable.
  3. The new /PC directory contains files to compile and test the code on Windows operating systems.
  4. The AMSOL executables for Mac OS 10.2.8 and Windows98/NT/2000/XP are now distributed.
  5. The amsol.compile script now has the option to automatically configure and compile the source code.
  6. A script ( that runs all the test runs has been put in the /test directory.

VERSION 6.9 (MARCH 2003)

  1. The algorithm that calculates the solvent-accessible surface area (SASA) has been modified to minimize discontinuities in the gradient of the G-CDS contribution to the free energy of solvation that have been observed in several cases. See Section 7.2 of this manual for more details. Appropriate modifications have been made in subroutine DAREAL.
  2. Analytical gradients for the SM5.2 and SM5.42 methods were implemented. Subroutine SM5RHB, located in the file sm5rhb.f was modified accordingly. In addition, subroutine kwnono.f was modified so that keywords SM5.x (where x=2 or x=42) and DERISA (the keyword to request analytical gradients) are allowed in the same input. Starting with this version of AMSOL, analytical gradients are used by default for calculations using the SM5.2 and SM5.42 models. A test calculation that tests the compatibility between the SM5.2 and DERISA keywords has been added (tr18d.dat) to the test suite. A test calculation that tests the compatibility between the SM5.42 and DERISA keywords has also been added (tr41d.dat) to the test suite.
  3. The '-O' optimization flag was added to the compile command for the linux option in the amsol.compile script.

VERSION 6.8.1 (MARCH 2003)

  1. This version of AMSOL corrects a bug associated with the SM5.2 keyword. Versions of AMSOL previous to 6.8.1 did not recognize the SM5.2 keyword as a valid keyword. This has been corrected with a few minor modifications in the file reads.f. A new test calculation, which tests the SM5.2 keyword, was added to the test suite. The new test calculation is called tr43.dat.
  2. The mechanism by which AMSOL determines whether or not the input options are mutually compatible has been found to fail in certain instances, so this mechanism has been simplified in this version of AMSOL. A new routine, called STPJOB, located in the file stpjob.f, was created.
  3. The Gauss-Legendre quadrature, which is used to calculate the effective Born radii, was not enabled for calculations using the SM5.2R, SM5.2, SM5.4, SM5.42R, and SM5.42 models. This has been corrected in this version of AMSOL.
  4. Minor modifications were made to the amsol.compile script in order to make the 'sun' option (the option used to compile AMSOL on Sun workstations) work properly.


  1. The CM3 charge model for AM1 and PM3 were implemented. For more information, see "Parameterization of Charge Model 3 For AM1, PM3, BLYP, and B3LYP" Thompson, J. D.; Cramer, C. J.; Truhlar, D. G. J. Comput. Chem. , 2002, submitted.
  2. The compile flags '-finit-local-zero -fno-automatic' were added to the linux option in amsol.compile. These flags initialize all local variables subroutine in AMSOL. Without these flags, several test suite calculations do not give correct results or get caught in an infinite loop on the linux implementation of AMSOL.

VERSION 6.7.2 (January 2002)

  1. The correct values of the SM5.42 surface tension parameters were added. For more details, refer to "Parameterization of a Universal Solvation Model for Molecules Containing Silicon", Winget, P.; Thompson, J. D.; Cramer, C. J.; Truhlar, D. G. J. Phys. Chem. B, 2002, submitted for publication.

VERSION 6.7.1 (October 2001)

  1. The script, amsol.compile was modified so that the Compaq option added in version 6.7.1 works properly.
  2. The parameter list for the calls to subroutine VECPRT and subroutine MATOUT in subroutine POLAR contained constants that are potentially changed in these two subroutines. When these constants are changed, it causes a segmentation fault with the Compaq version of AMSOL. Therefore, these constants are assigned to dummy variables, and these variables are passed into VECPRT and MATOUT. Upon further inspection, it appears that this is the only occurence of constants being modified when they are passed from one routine to another in the AMSOL source code.
  3. The -OPT compile flag was removed from the set of compile flags used to compile the SGI version of AMSOL. This flag performs certain performance optimizations of the code at compile time. However, it leads to unknown errors for at least three test suite calculations, namely tr03a, tr03n, and tr14.

VERSION 6.7 (September 2001)

  1. The Compaq option was added to the amsol.compile script. Details on the operating system, compiler version, and compiler options used are given in section 15.
  2. The file sm5rhb.f and prareas.f were changed to include the area COT functions and the parameters for Si and O-Si.
  3. Silicon parameters were added for the SM5.42R and SM5.42 models with the AM1 and PM3 parameterizations.
  4. Test runs tr42a (orthosilicic acid in water) and tr42n (orthosilicic acid in 1-octanol) were added.

VERSION 6.6 (December 1999)

  1. Printing of the Coulomb integrals, effective Born radii, Born polarization energies, and unchanged geometries (when liquid-phase calculations are performed without re-optimizing the geometry) are no longer default options. The keywords PRINTCOUL, PRINTRAD, PRINTPOL, and PRINTGEOM must be used to accomplish these actions.

VERSION 6.5.3 (September 1998)

  1. The manual was updated to reflect the fact that the keyword T=x has been replaced by TLIMIT=x.
  2. In file wrtkey.f, two write statements were added to echo keywords FACARB and FEHALO when used as input.
  3. Subroutine XYZINT was modified to fix a problem of the conversion from Cartesian coordinates to internal coordinates when three or more atoms are colinear. The modified routine was moved from ampac_unmod.f to a new file xyzint.f under the directory "new".
  4. On line 228 in file sm5rhb.f, "RTKK=" was changed to "RTKK=RTKK+". This change is necessary to make it agree with the published surface tension functional form for N triple bonded to C and avoid potential problems caused by the old code. Fortunately, the change does not affect AMSOL results for solutes in the parameterization sets. Those results were generated correctly by the old code.

VERSION 6.5.2 (June 1998)

  1. The 1SCF keyword was romoved from test input files tr28n.dat, tr29a.dat, and tr38a.dat. In files tr31a.dat and tr31n.dat, SM5.42 was replaced by the correct keyword SM5.42R. The keyword AM1 was added to files tr32a.dat and tr33a.dat.
  2. The solv.txt file has been modified to give correct FC and FH values for carbon tetrachloride, dibromomethane, and iodobenzene.

VERSION 6.5.1 (February 1998)

  1. In file ebrglq.f, the declaration of arrays was placed before the DATA statement.

VERSION 6.5 (February 1998)

  1. The SM5.0R model for organic solvents was added to the code.
  2. The SM5.2R model for use with the MNDO, AM1, and PM3 Hamiltonians for water and organic solvents were added to the code.
  3. The CM2 charge model was added to the code.
  4. The SM5.42R model was added for use with the AM1 and PM3 Hamiltonians for water and organic solvents.
  5. The amsol.compile script was modified to include options for compiling the code for Linux. The order of some statements (DATA statements and declarations of arrrays) was changed to prevent compiler errors under Linux.