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HOME PAGE OF DR. NAYANA VAVAL

 

 

 

 

 

 

 

 

Scientist, Physical Chemistry Division.

Education: B.Sc. (Physics), 1987, University of Pune; M.Sc. (Physics), 1990, University of Pune; Ph. D. (Physics), 1996, National Chemical Laboratory, Pune, India.

Postdoctoral, University of Eindhoven, Netherlands, 1998; Research Associate  June 2000 to July  2000 at Institute of Inorganic Chemistry, Slovak Academy of Sciences, Slovakia; Research Associate Aug 2000 till June 2001 national Chemical Laboratory, India; University of North Carolina A&T, North Carolina, 2002, USA.

Alexander von Humboldt Fellowship in Germany from June 2005 - June 2006.

 

 

    
 
   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Highlights of Research contributions:

The research contributions so far have been in a significant area of theoretical study of nonlinear molecular properties and spectra. The contributions of electron correlation have been studied at a depth using extensive many- body methods. In particular, correlation effects for demanding open shell situations have been addressed.

       During the PhD work at NCL Pune, approximately variational coupled-cluster based functionals were studied for computation of nonlinear molecular properties. These were based on a stationary principle and thus were suitable for higher-order properties. The functionals studied were expectation value and extended coupled cluster functionals. While the expectation value functional was observed to have several shortcomings due mainly to its nonterminating nature and disconnected nature of the equations. However, the extended coupled cluster functional does not suffer from the above limitations. This functional was studied extensively. General  purpose codes involving this were written in coupled cluster singles and doubles approximation. Also, during this period, multi-reference variants of coupled-cluster were used for accurate evaluation of excitation and ionization energies. 

        Current interests include a more complete development of extended coupled-cluster functional. In particular, the only problem that this functional had was that it involves twice the number of amplitudes and thus a coupled scheme of solution was considered expensive.  She is  introducing a de-coupled approximation for extended coupled cluster functional. Thus this approximation could be more useful for big systems. In all the previous schemes we used non-relaxed orbitals. It was observed that the relaxation effects are important for properties away from equilibrium. Thus to take care of orbital relaxation for analytic energy derivatives by introducing the coupled perturbed Hartree Fock (CPHF) approximation for this functional. With this new development along with the introduction of non-iterative triples should give the properties away from equilibrium more accurately.  This work is currently under the development.

        She had  worked on advanced and more complicated areas like multi-reference based coupled cluster methods. She developed the codes based on Fock space multi-reference coupled cluster method to calculate the difference energies i.e ionization potential and excitation energies which includes the partially effect of triples. The full inclusion of triples for these is under progress. Full inclusion of triples needs a detailed and careful computational effort. 

        Apart from the development of new codes, She is  involved computation of ground and excited state properties of dipole bound systems i.e water dimer, hydrogen fluoride dimer and water-HF dimer. These weakly bound systems are known to bound an excess electron in the dipole field of the electropositive atom. For the computation of  excited state molecular properties, She used the Fock space multi-reference coupled cluster method in finite field approximation. She is  also interested in the computation electron affinity of these systems using wave-function based methods.

        She is  also familiar with the molecular dynamics code of Car and Parrinello. During her post doctoral work in University of Eindhoven she worked on the introduction of the wavelet basis in quantum chemistry.

        Currently she is  involved in accurate calculations of Magnetic properties of small/ medium size molecules using coupled cluster method.

Professional recognition, awards, fellowship received:

SERC fast Track Proposal for Young Scientist 2000-2001 Scheme, titled " Design of non-linear optical molecular materials  using ab-initio method is been approved by DST (Department of Science and Technology).

Paper titled " Multi-reference coupled cluster based analytic response approach for evaluating molecular properties: Some pilot results", J. Chem. Phys, 110, 2316-2322 by D. Ajitha, Nayana Vaval and Sourav Pal received the best paper awards of the NCL Research Foundation in Physical Sciences for 1999.

Articles in Journals / Contribution to Books

  1. Sourav Pal, Nayana Vaval and R. K. Roy The principle of maximum hardness :An ab initio  study, J. Phys. Chem.,  97, 4404-4406(1993)

  2. Nayana Vaval, K. B. Ghose, Sourav  Pal and D. Mukherjee Fock space multireference coupled cluster theory:  Fourth order corrections to ionization potential , Chem. Phys. Lett., 209, 292-298(1993)

  3. Nayana Vaval, R.K. Roy and Sourav Pal, On stationary multideterminantal coupled cluster response, Phys. Rev. A, 49,  1623-1628(1994)

  4. Nayana Vaval, K.B.Ghose, P.G.Nair and Sourav Pal,  Stationary coupled cluster response :      role of  cubic terms in molecular properties, Proc. Indian  Acad. Sciences, 106, 387-392(1994)

  5.  Nayana Vaval, K.B.Ghose and Sourav Pal , Nonlinear molecular properties using biorthogonal response approach, J. Chem. Phys., 101, 4914-4919(1994)

  6.  Nayana Vaval and Sourav Pal, Stationary coupled cluster approaches to molecular properties : A comparative study, Phys. Rev. A, 54,  250-258(1996)(E) 55, 2482-2482

  7. Sourav Pal and Nayana  Vaval, Stationary coupled cluster functionals in molecular property calculations, Indian J. Chem., 35A, 721-727(1996)

  8. Sourav Pal and Nayana Vaval Analytic coupled cluster based response approach using multi determinantal model space, in Recent advances in coupled cluster methods, Ed R. J. Bartlett, World Scientific Publishing, Singapore, pg 255 - 273(1997)

  9. Nayana Vaval, Sourav Pal and D. Mukherjee Fock space multi reference theory: Approximate inclusion of triples for excitation energies, Theor. Chem. Acct., 99, 100-105(1998)

  10. Aparna Kumar, Nayana Vaval and Sourav Pal Extended coupled cluster functional for molecular properties: Study of an analytical and numerical approach, Chem. Phys. Lett. 295, 189(1998)

  11. D. Ajitha, Nayana Vaval and Sourav Pal Multi reference coupled cluster based analytic response approach for evaluating molecular properties: Some pilot results, J. Chem. Phys. 110, 2316(1999)

  12. Nayana Vaval and Sourav Pal Molecular property calculation of quasidegenerate systems using multi-reference coupled cluster approach, Chem. Phys. Lett. 300, 125(1999)

  13. Nayana Vaval and Sourav Pal Adiabatic states of ozone using   multi-reference coupled-cluster method,  J. Chem. Phys. 111, 4051(1999) 

  14. Nayana Vaval Molecular properties using bi-orthogonal functional: A de-coupled approximation, Chem. Phys. Lett, 318, 168-172(2000)

  15. Nayana Vaval, Aparna Kumar and Sourav Pal Extended coupled-cluster approach for molecular properties: Study of H2O and HF complexes, Int. J. Mol. Sci, 2, 89-102(2001)

  16. Nayana Vaval and Sourav Pal Study of constant term for electron- molecule scattering: F2, H2CO and H2O target examples, Chem. Phys. Letters, 345, 319-324(2001)

  17. Sourav Pal and Nayana Vaval Electric properties of molecules using stationary coupled cluster method, Recent. Res  Devel.  In Physical Chem, 6,527-542(2002)

  18. Nayana Vaval, Solomon Bililign and Robert J. Gdanitz Density functional study on the structure and stability of positive iron rare-gas complexes, Fe+Xn (X=Ar, Xe; n=1,6) ,Chem. Phys, 290, 171-176(2003)

  19. Y. Sajeev, M. Mishra, N. Vaval and Sourav Pal Fock space multi-reference coupled cluster calculations based on an underlying bi-variational self consistent field  on auger and shape resonance, J. Chem. Phys, 120, 67-72(2004)

  20. Prashant Manohar, Nayana Vaval and Sourav Pal Extended coupled cluster approach for magnetizabilities of small molecules, Chem. Phys. Lett. 387, 442- 447(2004)

  21. Nayana Vaval and Sourav Pal, Molecular properties using extended coupled-  cluster approach : Inclusion of orbital relaxation effects, Chem.Phys.Lett. 398, 194-200(2004)

  22. Sourav Pal and Nayana Vaval  Electric properties of molecules using stationary coupled cluster, J. Computational Methods in Science &Engg 4, 1-16(2004)

  23. Electronic Spectra and Ionization Potentials of Halogen oxides using the Fock-space Coupled-cluster method N. Vaval, P. Manohar and S. Pal; Collect. Czech. Chem. Commun. 70 (2005) 851-863

Published Contributions to Academic Conferences

  1. Nayana Vaval, K.B. Ghose and Sourav Pal Molecular properties using different coupled cluster functionals, in Abstract of International symposium on Spectra, Structure  and Dynamics ,Calcutta, P. 3-3(1994).

  2. Nayana Vaval, K.B.Ghose and Sourav Pal A critical study of different functionals for molecular properties, in Abstract of International discussion meeting on time dependent quantum mechanics of many electron systems, JNCASR, Bangalore, P. 1-1 (1996).

  3. Nayana Vaval and Sourav Pal Molecular properties of electronic excited states of H2O  using Fock space multireference coupled cluster method, in Abstracts of XII International conference on computers in chemical Research and Education held at Pune University, Pune , P. 97-97 (1998).

  4. Aparna B Kumar, Nayana Vaval and Sourav Pal Extended coupled cluster response method with inclusion of approximate triply excited amplitudes, in Abstracts of XII International conference on computers in chemical Research and Education held at Pune University, Pune, P. 123-123(1998).

  5. D. Ajitha, Nayana Vaval and Sourav Pal Molecular properties using the multi-reference coupled cluster method, in Symposium on Structure and Dynamics held at Indian Association for the Cultivation of Science , Calcutta(1998).

  6. Nayana Vaval and Sourav Pal Correlated static exchange interaction for electron molecule scattering, in 2nd National Symposium in Chemistry held at Indian Institute of Chemical Technology, Hyderabad(2000). 

  7.  D. Ajitha, Nayana Vaval and Sourav Pal Linear response to multi-reference coupled-cluster wave function: Excited state properties, in Xth International Congress of Quantum Chemistry, Menton, France   (2000).

  8. Nayana Vaval and Sourav Pal Property calculations using extended coupled cluster method: Inclusion of orbital relaxation effects, in 3rd National Symposium in  Chemistry held at Panjab University, Chandigarh(2001).