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(Seminar) The structure, anomalies, and criticality of liquid water
09/03
2020
- Title (Seminar) The structure, anomalies, and criticality of liquid water
- Speaker
- Date
- Venue
Abstract
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CAS Key Laboratory of Theoretical Physics | ||
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Institute of Theoretical Physics | ||
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Chinese Academy of Sciences | ||
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Seminar | ||
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Title 题目 |
The structure, anomalies, and criticality of liquid water | |
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Speaker 报告人 |
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Affiliation 所在单位 |
浙江大学
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Date 日期 |
2020年9月3日（周四）下午16:00 | |
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Venue 地点 |
新楼 6420 | |
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Contact Person 所内联系人 |
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Abstract 摘要 |
Water is the essential liquid on earth since it not only plays vital roles in living systems but also has a significant impact on our daily life. However, the unusual properties of liquid water, if compared with other liquids, has puzzled us for centuries because the basic structure of liquid water has remained unclear and has continued to be a matter of serious debate. Here, by computer simulations of three popular water models and the analysis of recent scattering experimental data, we show that there are two overlapped peaks hidden in the apparent “first diffraction peak” of the structure factor. This finding proves the coexistence of two types of local structures and thus, supports the two-state scenario for liquid water. Then, we make a comprehensive analysis of a large set of experimental structural, thermodynamic, and dynamic data based on a hierarchical two-state model. Our model predicts that a new line of maximal dynamical fluctuations should cross the Widom line of maximal thermodynamic fluctuations only at the liquid-liquid critical point (LLCP). This prediction, supported by hundred-microsecond simulations as well as recent experimental measurements on the compressibility and diffusion coefficient in the no man’s land, allows us to locate the LLCP around 184 K and 173 MPa. Nevertheless, we find that the influence of the criticality is almost negligible in the experimentally accessible liquid state of water because it is too far away from the LLCP. Our findings would provide a clue to solve the long-standing mystery of water. | |