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papers [2019/03/04 13:45] – janettate | papers [2020/03/06 09:12] (current) – external edit 127.0.0.1 | ||
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===== Poster assignment ===== | ===== Poster assignment ===== | ||
- | Summarize your results as a poster to be shown during class (date will be posted on the main calendar of the course). This is a conference of your peers, and may also be attended by interested parties such as former and prospective PH575 students, and faculty. OSU Student Media Services, located in the Valley Library, | + | Summarize your results as a poster to be shown during class (date will be posted on the main calendar of the course). This is a conference of your peers, and may also be attended by interested parties such as former and prospective PH575 students, and faculty. |
+ | |||
+ | OSU Student Media Services, located in the Valley Library, | ||
+ | |||
+ | Posters should be uncluttered, | ||
+ | * Here's [[http:// | ||
+ | * Michael Alley has useful things to say about [[https:// | ||
+ | * [[https:// | ||
===== Paper assignment ===== | ===== Paper assignment ===== | ||
- | After the poster session, you will write a paper that describes your findings. The feedback you get from the poster should help you write a better | + | After the poster session, you will turn in a paper that describes your findings |
- | General things | + | General things |
* the paper distills the knowledge you have gained about electronic structure, | * the paper distills the knowledge you have gained about electronic structure, | ||
- | * the paper would be helpful to an audience of incoming | + | * the paper would be helpful to an audience of incoming PH575 students. |
* the paper shows evidence of your scientific curiosity, and your ability to explain essential concepts. | * the paper shows evidence of your scientific curiosity, and your ability to explain essential concepts. | ||
- | Specific | + | Specific |
* Good discussion of what your calculations show. | * Good discussion of what your calculations show. | ||
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If you have questions, please ask! I will almost always email the whole class with my answer, or post the answers here under FAQ. | If you have questions, please ask! I will almost always email the whole class with my answer, or post the answers here under FAQ. | ||
- | |||
- | ===== Paper/ | ||
- | |||
- | Audience? | ||
- | |||
- | You are writing a scientific article for an audience of your peers, e.g. incoming PH575 students. You and your peers are highly educated, technically savvy people, but you do not know everything about every material that has ever been discovered. You are educating your peers about a particular material that is of scientific interest or technological importance and you want to convey what is interesting or important about that material from the point of view of a scientist. You are all capable of reading and understanding articles in any of the journals on solid state physics or materials. | ||
- | How to go beyond the basics? | ||
- | |||
- | Here are some ideas that might stimulate your creativity | ||
- | |||
- | explore another option within OpenMX | ||
- | pose a question that could be explored using this new tool | ||
- | study a family of materials | ||
- | go beyond the standard “default clicks” in OpenMX to explore something you found interesting | ||
- | choose a more challenging material (not always recommended because this is often an all-or-nothing proposition). | ||
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- | What materials have people chosen before? | ||
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- | Here is non-comprehensive list of materials that people have chosen in the past. | ||
- | xx | ||
- | yy | ||
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- | Talk to others to help point you to information, | ||
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- | Please do not perform the other person' | ||
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- | Don't work together to construct your posters - the temptation to produce the same format is very strong. This is your poster. But critique someone' | ||
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- | Length of paper? | ||
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- | Depends somewhat on the choice of topic and how many figures you include. Typical papers in the past have been about 8 pages including figures and references. | ||
- | Color printing? | ||
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- | You should use color - it makes a huge difference in crystal structures, band structures, DoS plots etc. | ||
- | Why a poster as well as a paper? | ||
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- | It's so that you can share your work with the other students and learn something from them, too. Science is about communicating ideas and results, so you need to practice that. So come up with something interesting to tell your peers. | ||
- | Pitfalls? | ||
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- | Don't write a technical manual (for example, “go to this menu, and click this button”). | ||
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- | Beware of the “true statements” trap. Just because you say true things does not mean a paper is well constructed or a valuable learning tool. You may have gleaned a piece of information from a well-respected paper in a reputable journal, but quoting that authority without integrating the information into the flow and design of your paper is not helpful. | ||
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- | Don’t think of the PH575 instructor as your audience. The instructor may give the paper to a colleague in chemistry or electrical engineering, | ||
- | How do I know my band structure is right? | ||
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- | Look in the literature - someone else is bound to have calculated it. Results will vary a bit with different methods used. Remember to reference others' | ||
- | My material has 80 atoms per conventional unit cell - is that OK? | ||
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- | 80 atoms is too big, however, check whether the primitive unit cell has fewer atoms. By trying to do computations with too many atoms you'll use all the memory and tie up the system so no one can use it. Not good! | ||
- | Can I study doping, (eg B-doped Si) or solid solutions like ZnS_(1-y)Se_y? | ||
- | |||
- | No, it's best to stay away from these because you will need a much larger unit cell. This is because if you replace say 1% of Si with P, you will need 100 atoms in your system (99 Si and 1 P) to define the basic unit. Refer to the question above. | ||
- | Can I study graphene? | ||
- | |||
- | During class time we will study several properties of graphene using analytical theory. Your poster will be boring if you reproduce the same things we've already done in class. However, you might have a good idea how you could use OpenMX to answer questions that go beyond the graphene calculations we do in class. | ||
- | Can I study conductivity as a function of temperature? | ||
- | |||
- | No. All calculations are inherently T = 0 calculations. There are no excitations of the system included. | ||
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- | One of the goals of the course is to become familiar with modern computational software that solves difficult problems in solid state Physics. You will use the software package OpenMX to calculate the band structure of a semiconductor, | ||
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- | Write a **paper** that describes your findings. | ||
- | |||
- | Summarize your results as a **poster** for the group to be shown in the hour reserved for MT2. This is a conference of your peers, and may also be attended by interested parties such as former and prospective PH575 students, and faculty. | ||
- | |||
- | If you have questions, please ask! I will almost always email the whole class with my answer, or post the answers here under FAQ. | ||
====== FAQ ====== | ====== FAQ ====== | ||
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Here are some ideas that might stimulate your creativity | Here are some ideas that might stimulate your creativity | ||
- | * explore another option within | + | * explore another option within |
* pose a question that could be explored using this new tool | * pose a question that could be explored using this new tool | ||
* study a family of materials | * study a family of materials | ||
- | * go beyond the standard " | + | * go beyond the standard " |
* choose a more challenging material (not always recommended because this is often an all-or-nothing proposition). | * choose a more challenging material (not always recommended because this is often an all-or-nothing proposition). | ||
=== Collaboration or no? === | === Collaboration or no? === | ||
- | Teach each other about how use the Wien and Flair basics. | + | Teach each other about how use OpenMX |
Talk to others to help point you to information, | Talk to others to help point you to information, | ||
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Yes! Here is the advice from previous years. | Yes! Here is the advice from previous years. | ||
- | Q. What is a CIF file | + | |
+ | Q. What is a CIF file? | ||
A. The Crystallographic Information File (CIF) is the standard for crystallographic data exchange prescribed by the International Union of Crystallography. It was described in a paper in Acta Cryst. (1991). A47, 655–685 by S. R. Hall, F. H. Allen and I. D. Brown. | A. The Crystallographic Information File (CIF) is the standard for crystallographic data exchange prescribed by the International Union of Crystallography. It was described in a paper in Acta Cryst. (1991). A47, 655–685 by S. R. Hall, F. H. Allen and I. D. Brown. | ||
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Here is some of the text from a CIF file describing anatase TiO2: | Here is some of the text from a CIF file describing anatase TiO2: | ||
- | _atom_site_label | + | '' |
- | _atom_site_type_symbol | + | |
- | _atom_site_fract_x | + | '' |
- | _atom_site_fract_y | + | |
- | _atom_site_fract_z | + | '' |
- | _atom_site_occupancy | + | |
- | _atom_site_U_iso_or_equiv | + | '' |
- | Ti1 Ti+4 0 0 0 1 0.0 | + | |
- | O1 O-2 0.2821 0.2821 0 1 0.0" | + | '' |
+ | |||
+ | '' | ||
+ | |||
+ | '' | ||
+ | |||
+ | '' | ||
+ | |||
+ | '' | ||
Translating the above code into english: “There is a Ti atom at (x,y,z) = (0,0,0) and an O atom at (0.2821a, 0.2821b, 0), where a and b are unit cell dimensions. | Translating the above code into english: “There is a Ti atom at (x,y,z) = (0,0,0) and an O atom at (0.2821a, 0.2821b, 0), where a and b are unit cell dimensions. |