Preface to the LPF Multinaries Edition - 2009 in Springer Materials

One of the most challenging tasks in materials science is the design of new materials with distinct properties. In general, two different approaches are explored:

1. The first approach is to simulate the motion of the atoms in the material, as well as their electronic interactions, and as close to reality as possible, by using calculations on the quantum-mechanical level. This is an extremely demanding task, especially if calculation of the property under investigation requires long-term simulation. However, at least in theory, there is no input other than the laws of quantum mechanics, so by using these calculations the material properties can be understood right away, from first principles. Based on this understanding, it should be possible to design new materials with distinct properties, simply by employing computer simulations.
2. At first glance, the second approach seems to be less challenging, as it does not ask for the really fundamental principles but rather remains on a more pragmatic level. Most of our current knowledge in chemistry and materials science has been collected empirically, simply by searching for patterns and rules in experiments, the results of which have been published in the literature. During the past 100 years or so, a huge amount of various types of corresponding data, such as crystal structures, powder diffraction patterns, phase diagrams and physical properties, has been collected for a large variety of compounds. This information is mostly also available in some materials databases. Beside the classical use of these databases for analysis, phase identification and teaching purposes, it should be worthwhile trying to use modern computer technology to search for additional rules and correlations implied in these data, and to use them in materials design.

Both approaches have their own advantages and problems. While the first approach (at least, in principle) does not rely on experiments and should result in a really deep understanding of fundamental correlations in solids, it is computationally extremely demanding, and currently can only be applied to a limited number of rather simple solids.

The second approach requires far less computational effort, and may thus (at least initially) lead to a faster success; however, it is extremely dependent on the availability of a sufficiently large number of experimental data of appropriate quality. An additional problem concerning this second empirical approach is that, until now, the relevant data types have been stored in separate, isolated databases, each using its own proprietary retrieval software. This has not only made the investigations rather tedious, but also has prohibited the user from performing an overall data analysis in order to discover hidden patterns and correlations.

These shortcomings of the empirical approach provided the basic motivation for the initiation of the Pauling File project, which started in 1995 as a collaboration between the Japan Science and Technology Corporation (JST), Tokyo, Japan, the Material Phases Data System (MPDS), Vitznau, Switzerland, and The University of Tokyo, RACE, Japan. The project includes two steps:

1. The first step is to create and maintain a comprehensive materials database for all non-organic (no C-H bonds), solid-state materials (systems), covering crystallographic data, phase diagrams, diffraction patterns, and physical properties. An important aspect, along with completeness, is the quality of the data acquired; these must be checked with extreme care, as unrecognized errors will at least confuse the correlation tools, and at most result in the deduction of wrong rules.
2. Parallel to the database creation, an appropriate retrieval software has been developed which renders the four different groups of materials data mentioned above accessible by a single user interface.

The current Pauling File online version, as integrated in SpringerMaterials, is called the "Multinaries Edition – 2009". It contains

• 32 000 binary and ternary phase diagrams (with updated phase assignment) covering 6 900 element systems,
• 180 000 structural data sheets (including atom coordinates and displacement parameters, when determined) for more than 110 000 different phases from 44 000 element systems, and roughly 13 000 experimental diffraction patterns,
• around 65 000 entries on physical properties (with about 210 000 numerical values and about 65 000 figure descriptions) for 95 physical properties of some 30 000 substances from 13 000 element systems.

To reach this result, the scientific editors have critically analyzed and processed about 100 000 original publications. Over 200 full-time manpower-years of editorial work has been necessary to edit the data for this LPF Multinaries Edition – 2009. Whereas, the coverage for crystal structures, diffraction data and phase diagrams can be considered as satisfactory, this is simply a beginning for property data. Nevertheless, the data contained in this release of LPF Multinaries Edition – 2009 is already equal to more than 250 000 printed pages — that is, a 250-volume Handbook!

We hope that you will appreciate this new approach to the fascinating world of inorganic materials, and would be glad to receive your comments and suggestions for further developments.

Finally, we would like to express our hearty thanks to Dr T. Ashino, Mrs R. Burkart, Mr S. D'Etraz, Mrs E. Flack, Mrs G. Fricker, Mrs R. Galliker, Dr A. Hannemann, Mrs G. Heer, Dr Y. Kaneta, Dr N. Koblyuk, Mr V. Luong, Mr S. Maddex, Mr H. Obergfell, Dr M. Penzo, Mr C. Rivera, Mrs L. Steiner, Mrs R. Steiner, Mrs I. Villars, Mr U. Villars, and Mr T. Vu. Special thanks also to the supporting staff of JST: Mr T. Atago, Dr Y. Chen, Mr K. Iijima, Mr H. Kaneko, Dr K. Kuroda, Dr C. Maeda, Mr M. Obara, Mrs R. Nakajima, Prof. N. Onodera, and Mr K. Yoshida.

Scientific Contributors: Jo Daams, Vitaliy Dubenskyy, Kensei Osaki, Oleh Shcherban (Crystal Structures), Alan Prince, Ihor Savysyuk (Phase Diagrams), Yurii Gorelenko, Stepan Popovych (Physical Properties)

Section Editors: Karin Cenzual (Crystal Structures), Hiroaki Okamoto (Phase Diagrams), Fritz Hulliger (Physical Properties)

Editor-in-Chief: Pierre Villars (e-mail: villars.mpds@bluewin.ch)

Project Coordinator: Shuichi Iwata

Pierre Villars, Material Phases Data System (MPDS), CH-6354 Vitznau, Switzerland, March 2012.

Shuichi Iwata, The University of Tokyo (UT), Tokyo, Japan, March 2012.