 TNPACK  the TruncatedNewton optimization package for multivariate nonlinear unconstrained problems.
The link below will bring you to the TNPACK code available from the Association for Computing Machinery through their journal:
Transactions on Mathematical Software (ACM TOMS).
Please contact the author, T. Schlick at schlick@nyu.edu if you have any questions.
ACCESS TNPACK
TNPACK publications
 The idea for the method tailored to molecular applications was first reported in 1987:


T. Schlick and M. Overton, "A Powerful Truncated Newton Method for Potential Energy Minimization", J. Comp. Chem., 8:10251039, May (1987) 

 The resulting FORTRAN package was submitted to ACM TOMS with two detailed papers in 1992:


T. Schlick and A. Fogelson, "TNPACK  A Truncated Newton Minimization Package for Large Scale Problems: I. Algorithm and Usage", ACM Trans. Math. Softw., 18:4670, March (1992) 



"T. Schlick and A. Fogelson, "TNPACK  A Truncated Newton Minimization Package for Large Scale Problems: II. Implementation Examples", ACM Trans. Math. Softw., 18:71111, March (1992) 

 Related work on modified Cholesky factorizations was published in 1993:


T. Schlick, "Modified Cholesky Factorizations for Sparse Preconditioners", SIAM J. Sci. Comp., 14:424445, March (1993) 

 TNPACK's incorporation into CHARMM with performance assessment was described in 1994:


P. Derreumaux, G. Zhang, B. Brooks, and T. Schlick, "A TruncatedNewton Method Adapted for CHARMM and Biomolecular Applications", J. Comp. Chem., 15:532552, April (1994) 

and into a meteorology package in 1993:


X. Zou, I. M. Navon, M. Berger, P. K. H. Phua, T. Schlick and F. X. Le Dimet, "Numerical Experience with LimitedMemory and Truncated Newton Methods", SIAM J. Opt., 3:582608, August (1993) 

 Further mathematical/computational improvements to handle indefinite preconditioners were reported in 1999:


D. Xie and T. Schlick, "Efficient Implementation of the Truncated Newton Method for Large Scale Chemistry Applications", SIAM J. Opt., 10: 132154 October (1999) 

 The updated package was subsequently submitted to ACM TOMS:


D. Xie and T. Schlick, "Remark on the Updated Truncated Newton Minimization Package, Algorithm 702", ACM Trans. Math. Softw., 25, 108122, March (1999) 

 More details on an improved line search were published in 2002:


D. Xie and T. Schlick, "A More Lenient Stopping Rule for Line Search Algorithms", Optim. Meth. Softw., in press, (2002) 

 For other applications of TNPACK to chemical design, see:


D. Xie, A. Tropsha and T. Schlick, "An Efficient Projection Protocol for Chemical Databases: Singular Value Decomposition Combined with TruncatedNewton Minimization", J. Chem. Inf. Comput. Sci., 40:167177, December (1999) 



D. Xie and T. Schlick, "Visualization of Chemical Databases Using the Singular Value Decomposition and TruncatedNewton Minimization", Optimization in Computational Chemistry and Molecular Biology: Local and Global Approaches, Volume 40, pages 267286, C. A. Floudas and P. M. Pardalos, eds., Kluwer Academic Publishers, Dororecht/Boston/London (2000) 

 For other applications of TNPACK to charge optimization, see:


D. A. Beard and T. Schlick, "Modeling SaltMediated Electrostatics of Macromolecules: The Discrete Surface Charge Optimization Algorithm and Its Application to the Nucleosome", Biopolymers, 58:106115 , January (2001) 

 For other applications of TNPACK to evolutionary trees, see:


T. Pinou, T. Schlick, B. Li, and H. Dowling, "Addition of Darwin's Third Dimension to Evolutionary Trees", J. Theor. Bio., 219:505512, October (1996) 

 For general reviews on optimization, including TNPACK, see:




T. Schlick, "Optimization Methods in Computational Chemistry", in Reviews in Computational Chemistry, Volume 3 , Chapter 1, pages 171, K. B. Lipkowitz and D. B. Boyd, eds., VCH Publishers, New York (1992) 



T. Schlick and G. Parks, "Mathematical Optimization'', contributed chapter to a scientific computing electronic textbook (``ebook") in DOE Computational Sciences Education Project, URL: http://csep1.phy.ornl.gov/csep.html (1994) 



T. Schlick, "Geometry Optimization", Contributed chapter to the Encyclopedia of Computational Chemistry (5 Volumes), Volume 2, pages 11361157, P. von Rague Schleyer, Editor in Chief and N. L. Allinger, T. Clark, J. Gasteiger, P. A. Kollman, and H. F. Schaefer III, eds., John Wiley & Sons, West Sussex (1998) 


