A negative curvature method is applied to nonlinear least squares problems with indefinite Hessian approximation matrices. With the special structure of the method, a new switch is proposed to form a hybrid method. Nu...A negative curvature method is applied to nonlinear least squares problems with indefinite Hessian approximation matrices. With the special structure of the method, a new switch is proposed to form a hybrid method. Numerical experiments show that this method is feasible and effective for zero-residual, small-residual and large-residual problems.展开更多
The Kohn-Sham density functional theory(KS-DFT)has played an important role in materials simulation for a long time.To better serve the industry,it is desirable to have an integrated solution that supports different c...The Kohn-Sham density functional theory(KS-DFT)has played an important role in materials simulation for a long time.To better serve the industry,it is desirable to have an integrated solution that supports different calculation tasks by KSDFT with different corrections and modifications.In this work,we present Hylanemos,a plane wave pseudopotential(PW-PP)KS-DFT package written entirely in the Julia programming language,which could offer such a solution.First,we analyze the code design to get the flexibility needed to implement such a solution.Then,we show that its accuracy and speed are comparable to widely-used packages.Next,we show its ability to perform common tasks such as single point(SP)calculations,geometry optimization,and transition state calculations.Finally,the LDA+Gutzwiller(LDA+G)method is presented,a feature not commonly found in DFT packages.In addition,we have also developed a set of ultrasoft(US)PP through parameter adjustment and optimization.This set of PP,called Eacomp PP,has a low cutoff energy(<18 Ha)and exhibits excellent performance in our benchmarks.Combining a performant package and optimized potentials will facilitate our in-depth efforts in promoting industrialization.展开更多
文摘A negative curvature method is applied to nonlinear least squares problems with indefinite Hessian approximation matrices. With the special structure of the method, a new switch is proposed to form a hybrid method. Numerical experiments show that this method is feasible and effective for zero-residual, small-residual and large-residual problems.
基金supported by the National Natural Science Foundation of China(Grant No.12426301)。
文摘The Kohn-Sham density functional theory(KS-DFT)has played an important role in materials simulation for a long time.To better serve the industry,it is desirable to have an integrated solution that supports different calculation tasks by KSDFT with different corrections and modifications.In this work,we present Hylanemos,a plane wave pseudopotential(PW-PP)KS-DFT package written entirely in the Julia programming language,which could offer such a solution.First,we analyze the code design to get the flexibility needed to implement such a solution.Then,we show that its accuracy and speed are comparable to widely-used packages.Next,we show its ability to perform common tasks such as single point(SP)calculations,geometry optimization,and transition state calculations.Finally,the LDA+Gutzwiller(LDA+G)method is presented,a feature not commonly found in DFT packages.In addition,we have also developed a set of ultrasoft(US)PP through parameter adjustment and optimization.This set of PP,called Eacomp PP,has a low cutoff energy(<18 Ha)and exhibits excellent performance in our benchmarks.Combining a performant package and optimized potentials will facilitate our in-depth efforts in promoting industrialization.
