QUASI: Quantum simulations in industry

• Research unit: EU RFP
• Project number: 97.0252

Key words (English)

Hybrid QM/MM methods; optimization; modeling; catalysis; enzymatic reactions; drug design

Alternative project number (English)

EU project number: EP 25047

Research programs (English)

EU-programme: 4. Frame Research Programme - 1.3 Telematic systems

Short description (English)

See abstract

Partners and International Organizations (English)

CCLRC Daresbury Laboratory (UK), BASF (D), ICI (UK),
Norsk Hydro (NO), Royal Institution (UK)

Abstract (English)

QUASI addresses the development of combined quantum mechanical (QM) and molecular mechanical (MM) methods, their implementation in a modular user-friendly high-performance computing environment, and their application to industrial catalysis in the fields of surface chemistry, biochemistry, and environmental chemistry. The project integrates software development in three academic groups and modeling activities in three major chemical companies.
In the second year of the project, the QUASI-2 code was generated and provided to the industrial partners. Our contributions to this code included the validation of the chosen QM and MM components, the comparison of different QM/MM coupling schemes and link atom approaches, and the implementation of our semiempirical MNDO97 program within QUASI-2.
As our main methodological task, we finished the development of an efficient and robust geometry optimizer for large systems with thousands of atoms. There are several key features in our approach: Different types of coordinates can be generated automatically (including nonredundant delocalized coordinates), hybrid cartesian and internal coordinates are introduced to allow for linear scaling divide-and-conquer optimizations (both in quasi-Newton minimizations and microiterative transition state searches), and user-chosen constraints as well as automatic error recovery are supported. The new optimizer has been fully implemented and validated in several applications[1].
In cooperation with our direct industrial partner (BASF) we have performed validation studies on enzymes involving both geometry optimizations and molecular dynamics simulations on QM/MM potential surfaces. The systems studied include thrombin-inhibitor complexes and triosephosphate isomerase. In the latter case, the relevant enzymatic reactions have been treated at semiempirical, density functional, and ab initio QM levels.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 97.0252