Siesta: Recent developments and applications

A review of the present status, recent enhancements, and applicability of the Siesta program is presented. Since its debut in the mid-1990s, Siesta?s flexibility, efficiency, and free distribution have given advanced materials simulation capabilities to many groups worldwide. The core methodological scheme of Siesta combines finite-support pseudo-atomic orbitals as basis sets, norm-conserving pseudopotentials, and a real-space grid for the representation of charge density and potentials and the computation of their associated matrix elements. Here, we describe the more recent implementations on top of that core scheme, which include full spin?orbit interaction, non-repeated and multiple-contact ballistic electron transport, density functional theory (DFT)+U and hybrid functionals, time-dependent DFT, novel reduced-scaling solvers, density-functional perturbation theory, efficient van der Waals non-local density functionals, and enhanced molecular-dynamics options. In addition, a substantial effort has been made in enhancing interoperability and interfacing with other codes and utilities, such as wannier90 and the second-principles modeling it can be used for, an AiiDA plugin for workflow automatization, interface to Lua for steering Siesta runs, and various post-processing utilities. Siesta has also been engaged in the Electronic Structure Library effort from its inception, which has allowed the sharing of various low-level libraries, as well as data standards and support for them, particularly the PSeudopotential Markup Language definition and library for transferable pseudopotentials, and the interface to the ELectronic Structure Infrastructure library of solvers. Code sharing is made easier by the new open-source licensing model of the program. This review also presents examples of application of the capabilities of the code, as well as a view of on-going and future developments.SIESTA development was historically supported by different Spanish National Plan projects (Project Nos. MEC-DGES-PB95-0202, MCyT-BFM2000-1312, MEC-BFM2003-03372, FIS2006-12117, FIS2009-12721, FIS2012-37549, FIS2015-64886-P, and RTC-2016-5681-7), the latter one together with Simune Atomistics Ltd. We are thankful for financial support from the Spanish Ministry of Science, Innovation and Universities through Grant No. PGC2018-096955-

How to verify the precision of density-functional-theory implementations via reproducible and universal workflows

In the past decades many density-functional theory methods and codes adopting periodic boundary conditions have been developed and are now extensively used in condensed matter physics and materials science research. Only in 2016, however, their precision (i.e., to which extent properties computed with different codes agree among each other) was systematically assessed on elemental crystals: a first crucial step to evaluate the reliability of such computations. We discuss here general recommendations for verification studies aiming at further testing precision and transferability of density-functional-theory computational approaches and codes. We illustrate such recommendations using a greatly expanded protocol covering the whole periodic table from Z=1 to 96 and characterizing 10 prototypical cubic compounds for each element: 4 unaries and 6 oxides, spanning a wide range of coordination numbers and oxidation states. The primary outcome is a reference dataset of 960 equations of state cross-checked between two all-electron codes, then used to verify and improve nine pseudopotential-based approaches. Such effort is facilitated by deploying AiiDA common workflows that perform automatic input parameter selection, provide identical input/output interfaces across codes, and ensure full reproducibility. Finally, we discuss the extent to which the current results for total energies can be reused for different goals (e.g., obtaining formation energies).Comment: Main text: 23 pages, 4 figures. Supplementary: 68 page

Common workflows for computing material properties using different quantum engines

The prediction of material properties based on density-functional theory has become routinely common, thanks, in part, to the steady increase in the number and robustness of available simulation packages. This plurality of codes and methods is both a boon and a burden. While providing great opportunities for cross-verification, these packages adopt different methods, algorithms, and paradigms, making it challenging to choose, master, and efficiently use them. We demonstrate how developing common interfaces for workflows that automatically compute material properties greatly simplifies interoperability and cross-verification. We introduce design rules for reusable, code-agnostic, workflow interfaces to compute well-defined material properties, which we implement for eleven quantum engines and use to compute various material properties. Each implementation encodes carefully selected simulation parameters and workflow logic, making the implementer’s expertise of the quantum engine directly available to non-experts. All workflows are made available as open-source and full reproducibility of the workflows is guaranteed through the use of the AiiDA infrastructure.This work is supported by the MARVEL National Centre of Competence in Research (NCCR) funded by the Swiss National Science Foundation (grant agreement ID 51NF40-182892) and by the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 824143 (European MaX Centre of Excellence “Materials design at the Exascale”) and Grant Agreement No. 814487 (INTERSECT project). We thank M. Giantomassi and J.-M. Beuken for their contributions in adding support for PseudoDojo tables to the aiida-pseudo (https://github.com/aiidateam/aiida-pseudo) plugin. We also thank X. Gonze, M. Giantomassi, M. Probert, C. Pickard, P. Hasnip, J. Hutter, M. Iannuzzi, D. Wortmann, S. Blügel, J. Hess, F. Neese, and P. Delugas for providing useful feedback on the various quantum engine implementations. S.P. acknowledges support from the European Unions Horizon 2020 Research and Innovation Programme, under the Marie Skłodowska-Curie Grant Agreement SELPH2D No. 839217 and computer time provided by the PRACE-21 resources MareNostrum at BSC-CNS. E.F.-L. acknowledges the support of the Norwegian Research Council (project number 262339) and computational resources provided by Sigma2. P.Z.-P. thanks to the Faraday Institution CATMAT project (EP/S003053/1, FIRG016) for financial support. KE acknowledges the Swiss National Science Foundation (grant number 200020-182015). G.Pi. and K.E. acknowledge the swissuniversities “Materials Cloud” (project number 201-003). Work at ICMAB is supported by the Severo Ochoa Centers of Excellence Program (MICINN CEX2019-000917-S), by PGC2018-096955-B-C44 (MCIU/AEI/FEDER, UE), and by GenCat 2017SGR1506. B.Z. thanks to the Faraday Institution FutureCat project (EP/S003053/1, FIRG017) for financial support. J.B. and V.T. acknowledge support by the Joint Lab Virtual Materials Design (JLVMD) of the Forschungszentrum Jülich.Peer reviewe

Organisation of Internal Control in a Budget Institution: Applied Aspect Организация внутреннего контроля в бюджетном учреждении: прикладной аспект вопроса

The article proves urgency and necessity of organisation of internal control in budget institutions. It graphically depicts a general structure of the organisation of internal control in budget institutions. It offers and substantiates a model of organisation of internal control in budget institutions. It proves that the key principles of organisation of internal control in budget institutions are principles of effectiveness and efficiency. Moreover, the effectiveness principle is connected with identification of an optimal number and the most expedient composition of the internal control department in a budget institution. Using economic and mathematical methods, the article calculates an optimal number and composition of such a department. It makes a conclusion that the internal control department of a budget institution should include 2 controllers of the third type and 2 controllers of the fifth type, while it is not expedient to include controllers of the first, second and fourth types. Besides, the wages fund should be minimal – UAH 6,800 per month.Доказана актуальность и необходимость организации внутреннего контроля в бюджетных учреждениях. Графически изображено общее построение организации внутреннего контроля в бюджетных учреждениях. Предложена и обоснована модель организации внутреннего контроля в бюджетных учреждениях. При этом доказано, что ключевыми принципами при организации внутреннего контроля в бюджетных учреждениях являются принципы экономичности и эффективности. К тому же, принцип экономичности связан с определением оптимальной численности и наиболее целесообразного состава отдела внутреннего контроля в бюджетном учреждении. С помощью экономико-математических методов рассчитана оптимальная численность и кадровый состав такого отдела. Сделан вывод, что в состав отдела внутреннего контроля бюджетного учреждения следует включить 2 работника третьего типа контроллеров и 2 работника пятого типа контроллеров, первый, второй и четвертый типы контролеров не целесообразно включать в отдел. При этом фонд заработной платы будет минимальный – в размере 6800 грн в месяц

Theoretical grounds of internal audit in the system of state financial control in Ukraine

The article considers modern directions of reformation of the system of state financial control connected with introduction of the state internal financial control. It considers economic essence of the state internal financial control in the context of its components. It justifies the place of the internal audit in the system of the state internal financial control in Ukraine. It considers existing definitions of internal audit in legislative acts. It generalises views of scientists on interpretation of the “internal audit” notion. It provides definitions united in approaches. It conducts a critical analysis of generalised approaches. It offers the authors’ view on the essence of internal audit in budget institutions, which has certain positive features compared to existing ones

Evaluation of Enterprise Financial Safety

The aim of the article is to develop a methodological approach to evaluation of the level of economic entity financial safety. It has been found that the enterprise activity is constantly subjected to internal and external threats, therefore under volatile market economic conditions it is important to form an effective system of management of its financial safety to avoid the bankruptcy and liquidation of the enterprise. The article presents a generalization of existing approaches to evaluating the level of financial safety of economic entities and their critical analysis. The methodical approach to evaluating the level of financial safety of economic entities is proposed. It is suggested to evaluate the level of financial safety qualitatively and quantitatively with the consequent comparing and contrasting of their results. It is proposed to carry out the quantitative evaluation by the method of fuzzy logic and the qualitative one by the method of hierarchy analysis. The evaluation of the level of financial safety was carried out at ten economic entities. It is determined that the qualitative evaluation of the level of business entity financial safety, unlike the quantitative one allows to determine not only the enterprise financial stability but also to assess its financial

Особливості діагностики рецидивів грижі міжхребцевих дисків у поперековому відділі хребта

Many methods are used to evaluate the state of lumbar spine after surgery. The current neuroimaging tool of choice is Gd-enhanced MR-imaging for postdisceсtomy recurrent symptoms investigation. To recognize postoperative pathological changes the doctor must be familiar with changes appropriate for early and late phases of postoperative period.При обследовании пациентов с рецидивом грыжи диска после хирургического лечения используют большое число методов. Наиболее информативным методом нейровизуализации как методом выбора при обследовании пациентов с рецидивом клинических проявлений после дискэктомии является магниторезонансная томография с усилением путем внутривенного введения препаратов на основе гадолиния. При распознавании послеоперационных патологических изменений врач должен знать признаки, характерные для ранней и поздней фаз послеоперационного периода.Під час обстеження пацієнтів з рецидивом грижі диска після хірургічного лікування використовують велику кількість методів. Проте, найбільш інформативним методом нейровізуалізації як методом вибору при обстеженні пацієнтів з рецидивом клінічних проявів після використання дискектомії, є магніторезонансна томографія (МРТ) з підсиленням шляхом внутрішньовенного введення препаратів на основі гадолінію. При розпізнаванні післяопераційних патологічних змін лікар має бути обізнаний щодо симптомів, характерних для ранньої та пізньої фаз післяопераційного періоду

ФИНАНСОВЫЙ КОНТРОЛЬ ВНЕШНЕЭКОНОМИЧЕСКОЙ ДЕЯТЕЛЬНОСТИ ПРЕДПРИЯТИЯ: ТЕОРЕТИКО-МЕТОДОЛОГИЧЕСКИЙ АСПЕКТ

If you need full access to the book, please write an email to the Publisher. Your request will be redirected to the author. If s/he is interested, s/he will directly contact you using the email address you have specified to discuss the conditions for obtaining access without the intermediary of the Publisher. The essence of finance, the activities of subjects of financial relations, the essence of financial control, the main provisions of the methodology of financial control in Ukraine are considered. The theoretical aspects of foreign economic activity are separately summarized. Particular attention is paid to financial control of foreign economic activity, including in the context of ensuring financial security; ways of developing financial control of foreign economic activity in Ukraine are proposed. Indexing:           Якщо Вам необхідно отримати повний доступ до книги, напишіть електронного листа Видавцю. Ваш запит буде переадресовано автору. У разі його зацікавленості, він безпосередньо зв'яжеться з Вами за вказаною Вами адресою електронної пошти для обговорення умов на отримання доступу без посередництва Видавця. Рассмотрена сущность финансов, деятельность субъектов финансовых отношений, сущность финансового контроля, основные положения методологии финансового контроля в Украине. Отдельно обобщены теоретические аспекты внешнеэкономической деятельности. Особое внимание уделено финансовому контролю внешнеэкономической деятельности, в том числе в контексте обеспечения финансовой безопасности, предложены пути развития финансового контроля внешнеэкономической деятельности в Украине. Індексація:          &nbsp