PhD Defense by Swarnava Ghosh

Event Details
  • Date/Time:
    • Thursday July 7, 2016
      10:30 am - 12:30 pm
  • Location: Sustainable Education Building, 122
  • Phone:
  • URL:
  • Email:
  • Fee(s):
    N/A
  • Extras:
Contact
No contact information submitted.
Summaries

Summary Sentence: Efficient Large-Scale Real-Space Electronic Structure Calculations

Full Summary: No summary paragraph submitted.

 

School of Civil and Environmental Engineering

 

Ph.D. Thesis Defense Announcement

Efficient Large-Scale Real-Space Electronic Structure Calculations

 

By

Swarnava Ghosh

 

Advisor:

Dr. Phanish Suryanarayana (CEE)

 

Committee Members:

Dr. Glaucio H. Paulino (CEE), Dr. Arash Yavari (CEE),

Dr. Ting Zhu (ME), Dr. John E. Pask (Lawrence Livermore National Laboratory)

 

Date & Time: Thursday, July 7, 2016, at 10:30AM

Location: Sustainable Education Building, 122

Calculations involving the electronic structure of matter provides valuable insight in understanding and predicting a wide range of materials

properties. Over the course of the last few decades, Density Functional Theory (DFT) has been a reliable and popular ab-initio method. The

plane-wave basis is commonly employed for solving the DFT problem. However, the need for periodicity limits the effectiveness of the

plane-wave basis in studying localized or partially periodic systems. Furthermore, efficient use utilization modern large-scale computer

architectures is particularly challenging due to the non-locality of the basis. Real-space methods for solving the DFT problem provide an

attractive alternative.

In this work we present an accurate and efficient real-space formulation and parallel implementation of Density Functional Theory (DFT) for

performing ab-initio simulations of isolated clusters (molecules and nanostructures), periodic (infinite crystals) and partially periodic systems

(slabs and nanowires). Using the finite-difference representation, local reformulation of the electrostatics, the Chebyshev polynomial filtered

self-consistent field iteration, and a reformulation of the non-local component of the force, we develop SPARC (Simulation Package for

Ab-initio Real-space Calculations), a framework that enables the efficient evaluation of energies and atomic forces to within chemical

accuracies in DFT. Through selected examples consisting of a variety of elements, we demonstrate that the developed framework obtains

exponential convergence in energy and forces with domain size; systematic convergence in the energy and forces with mesh-size to reference

plane-wave result at comparably high rates; forces that are consistent with the energy, both free from any noticeable `egg-box' effect; and

accurate ground-state properties including equilibrium geometries and vibrational spectra. We also demonstrate the weak and strong scaling

behavior of SPARC and compare with well-established and optimized plane-wave and other real-space implementations of DFT for systems

consisting up to thousands of electrons. Overall, the developed framework is able to accurately and efficiently simulate the electronic

structure of a wide range of material systems and represents an attractive alternative to existing codes for practical DFT simulations.



Additional Information

In Campus Calendar
No
Groups

Graduate Studies

Invited Audience
Public
Categories
Other/Miscellaneous
Keywords
Phd Defense
Status
  • Created By: Tatianna Richardson
  • Workflow Status: Published
  • Created On: Jun 22, 2016 - 9:57am
  • Last Updated: Oct 7, 2016 - 10:18pm