Symposium Present Status and Tangible Improvements of Ab-initio Electronic Structure Calculations

Academic Year 2019
Symposium
Present Status and Tangible Improvements of Ab-initio
Electronic Structure Calculations
November 18th - November 20th, 2019

Organizers:

Carlos F. Bunge	Instituto de Física, UNAM
Yenni P. Ortiz Acero	Instituto de Física, UNAM
Thomas H. Seligman	Instituto de Ciencias Físicas, UNAM
Laimutis Bytautas	Galveston College
Herzain I. Rivera	Facultad de Qímica, UNAM

Scope

People presently work, publish and talk about ab-initio electronic structure calculations taking for granted that usefull results can be obtained in a wide range of applications, however, most current calculations are not ab-initio and they are so much faster than ab-initio. This trend is becoming more and more permanent.

At high accuracy and equilibrium geometries we have coupled cluster (CC) calculations with triple to sextuple zeta size consistent orbital bases. Outside equilibrium, density matrix renormalization group and various configuration interaction (CI) schemes are used for very small molecules, while applications to most molecules of interest to within chemical accuracy (1 kcal/mol) are too costly or unreachable. On the other hand, more than forty years ago, relatively simple CI calculations on molecule were useful to detect shortcomings of old semiempirical methods. Could it be possible today to use simple CI to detect weaknesses in DFT calculations?

The main limitation of orbital methods in ab-initio work lies in the very slow convergence of Legendre's expansion for the reciprocal of the distance between two points r₁₂^-1. The asymtotic convergence of CI and CC calculations goes as L^-4 and it would be quite helpful to approximate r₁₂^-1 such that asymptotic convergence is postponed for very high values of L. That may allow orbital calculations with an accuracy comparable to the one achieved by Hylleraas-type methods but without the appearance of non-orthogonality.

Participation fee:

150 US Dollars, 75 US Dollars for students.
The conference fee includes coffee breaks, lunches and the conference dinner. The fee can be payed in US Dollars, Euros or Mexican Pesos. Cash and Travel checks are welcome. Personal checks and credit cards cannot be accepted. Please, contact the organizers if your situation requieres a waiver of these fees.

Venue and Housing:

The Gathering will take place at the Centro Internacional de Ciencias (CIC), which is located on the campus of the Universidad Autónoma del Estado de Morelos in Cuernavaca, Mexico.
A limited number of rooms is avaliable at the CIC guesthouse, located in the citycenter of Cuernavaca. The hotel "Posada de Tlaltenango" offers lodging at a special rate.

Program

Participants

Arrival Information:

Arriving at the airport in Mexico City, you can take an autobus going directy to Cuernavaca. The company is called "Pullman de Morelos. At terminal 1, the ticket counter is located inside the airport on the second floor (flights arrive on the first floor). At terminal 2, the ticket counter is located outside the arrival area. All busses leave from terminal 1, but stop at terminal 2. Buses operate from 4:00 to 0:30, approximately every 30 minutes. The ticket costs 300 Mexican Pesos (16 US Dollars). It takes about 90 minutes to Cuernavaca, depending on the traffic. You will arrive in Cuernavaca at the "Casino de la Selva" bus station, where you can take a taxi. We recommend to buy the taxi ticket inside the bus station at the counter. A taxi to the CIC guest house costs about 70 Mexican Pesos (4 US Dollars).
The address of the CIC guest house:
Calle Plutarco Elias Calles #20 (esq. con Amates)
Colonia del antiguo Club de Golf
Cuernavaca, Morelos
Tel: +52-777-3129913
(Additional information for the taxi driver if needed:
Dos cuadras al sur de la Comercial Mexicana MEGA de av. Morelos Sur.)

Financial Support by:

CONACYT PROYECTO 299134

CIC AC

UNAM-PAPIIT

ICF-UNAM

Please, visit this site regularly as dates and participants may change. We will do our best to keep the information up to date.

If you may have interest in participate in this gathering or if you have further questions please contact: yortiz(at)icf.unam.mx or leyvraz(at)fis.unam.mx