"Two-dimensional materials of the transition metal dichalcogenide family are relatively well-known in our materials community due to their wide tunability of electronic and optical properties."
In a conference room of School of Materials Science, Luo Mingya stood on the podium and wrote the words TMD.
At this time, she was introducing their topic to Xiao Yi in the audience.
Although Xiao Yi does not understand, it does not prevent him from bringing some concepts to him in this way to help him understand the purpose of the topic later.
And Xu Ming and the others are also here, sitting down and listening.
Of course, this also includes their mentor, Sun Lina.
After all, Sun Lina is the person in charge of this project, and the project funds were applied for in her name.
Now Xiao Yi has also learned through Xu Ming how powerful this Sun Lina was when he was young.
She is almost the same as the Luo Mingya standing above. She entered Gifted Class at the age of 15, and then she completed her undergraduate degree in only three years, so she entered graduate school at the same age of 18 as Luo Mingya. She completed her doctoral degree in MIT in four years, studied abroad for almost eight years, and then suddenly returned to China.
According to the gossip provided by Xu Ming, she suffered an emotional blow, so she chose to return to China. Of course, she had already been rated as a Qianqing before returning to China, and after returning to China, she became Outstanding Young Scholar. The total of various funds every year is stable at more than 10 million.
She failed, but she didn't fail completely. Occasionally she would take action if she really had a good direction. After returning to China, she had already produced a second-class National Natural Science Award and two top journals.
Basically, the status of their laboratory, relying on Sun Lina, is considered to be the top in their Institute of Materials Science, even the laboratories of academicians are not far behind.
It's just that when she shows off, she really shows off.
Xiao Yi They all looked back and saw Professor Sun sitting at the back, holding her switch and wearing headphones while having a picnic.
Then, according to Luo Mingya's temper...
"Sun Lina! If you don't want to hear it, you don't have to come here."
As expected, Luo Mingya glared over immediately.
Sun Lina then raised his head and glanced at Luo Mingya, waved his hand and said, "Don't worry about me, don't look at me playing games, I can actually hear what you are talking about, do two things at once, can you make something?"
Luo Mingya: "Sooner or later I have to complain to the dean about this terrible tutor."
Sun Lina: "It's okay. This year, almost a dozen companies are thinking of me and are planning to come to our school to hold a seminar. Domestic companies include Linde, Diaby, Warwick, and a bunch of foreign companies. This year's spring recruitment can help our college relieve a lot of employment pressure, so the dean will not trouble me."
Luo Mingya raised his eyebrows and said, "Very good, since you are so proud, it seems that I can go to Warwick and ask how seven-digit servers are sold, and maybe you can give me a few discounts."
"Just buy it, it costs so much..."
Sun Lina paused suddenly. "What number did you say?"
"It's not much. Our budget is eight figures, so I'll buy a seven figure one."
"Stop, my little ancestor, please stop asking."
Sun Lina finally put down the switch in his hand, "The laboratory's annual funding is only tens of thousands of dollars, and it's all done by you. How will you spend the next 10 months?"
"Hmph, then just listen to me honestly!"
Luo Mingya showed a victorious expression.
Sun Lina admitted defeat and sat down in the front honestly.
Luo Mingya continued, "Then next..."
At this time Xiao Yi raised his hand.
"What's wrong with Junior Brother Xiao?" Luo Mingya said.
"Excuse me, what the hell is this?"
Xiao Yi looked at the three letters TMD she wrote on the blackboard and was curious about what it meant.
Eliminate the most well-known answer first.
"Oh, you're talking about this." Luo Mingya smiled, "This is transition-metal dichalcogenide, abbreviated as TMD."
"That's it."
Xiao Yi nodded, and everyone present smiled knowingly.
The unexpected coincidence made the atmosphere in this conference room slightly more relaxed.
"I continue to say below." Luo Mingya said, "In short, this flexibility in the physical properties of TMD materials can be traced to its significant sensitivity to dimensionality, specific edge configurations and stacking sequences."
"The most common polytype stacking sequence in TMD materials..."
"Polytyping phenomena, unconventional crystal phases that display mixtures of stacking sequences, represent a powerful means of designing and engineering new physical properties in two-dimensional materials."
"Inspired by this, the most important thing about our project is to realize the first-principles calculation of the optoelectronic properties related to the 2H/3R polytype in WS2 nanomaterials."
"This is the purpose of our project. I don't know whether Junior Xiao has heard of the first principle that needs to be used in the process. It is the same as the Density Functional Theory I mentioned to you before, and it plays an important role in Computational Materials Science."
"It describes the behavior of atoms and electrons based on Schrödinger equation in Quantum Mechanics. It does not rely on experimental data and empirical parameters. It only needs to solve Schrödinger equation to predict and calculate the properties of materials."
Xiao Yi Listening to the other party's introduction, his eyes lit up. "Is it also involving physics? Quantum physics?"
Luo Mingya nodded and said with a smile, "Actually, our major is called Materials Physics and Chemistry."
"Materials themselves are between physics and chemistry, and computational materials is a materials direction that spans multiple fields such as chemistry, physics, computers, mathematics, etc., so no matter which discipline is used, it can help our research."
"So next you may also need to learn some knowledge about quantum physics."
Xiao Yi waved his hand. "It's not a big problem."
One is studying, and the other two are also studying, which is nothing more than reading.
This is how he learned mathematics, so it doesn't matter.
Luo Mingya nodded and glanced at Xiao Yi with great appreciation.
Compared with her junior brothers and sisters, they can't even stand reading a paper, and they don't know how Sun Lina recruited them. The key is that this woman doesn't teach them, and it will be her turn to teach in the end.
Tired.
Forget it, comparing Xiao Yi with them, they are too unworthy.
In terms of achievements in their respective fields, there is only a huge gap between her and Xiao Yi.
"Okay, these are the contents of our topic. Now our progress has reached the analysis of density of states and energy band structure, and the current problem is mainly focused on how to use computational methods to simulate them, so as to facilitate our research."
"I will send you the theoretical model we have determined now and our algorithm later. Well... you should know about algorithms and programs."
Xiao Yi nodded and said modestly, "I understand a little bit."
Xu Ming next to them rolled their eyes.
Your mining software can be valued by a mine boss with tens of thousands of mining machines. Does this mean you only have a little understanding of algorithm programs?
joke.
Luo Mingya nodded. "That's enough, Xu Ming, show Xiao Yi the model and algorithm."
"Hmm... Junior Brother Xiao, do you think there is any room for further optimization in the algorithm?"
Xu Ming opened his laptop, clicked on various files, and finally placed them in front of Xiao Yi.
"Brother Xiao, that's it."
Xiao Yi nodded and looked at it.
Although he didn't understand what the parameters inside represented, but from a purely mathematical perspective, he quickly made an evaluation. "The convergence speed and accuracy still need to be improved."
"Well... the numerical solution method used can be improved first. My suggestion is to consider using a more efficient iterative solver. Especially when dealing with large-scale matrices, introducing the multigrid method is a good direction."
"Multi-grid?" Xu Ming's eyes lit up, "This idea is indeed possible! The multi-grid method does very well when dealing with large-scale problems."
But soon he began to think again, "But the question is, how do we ensure that these improvements will not affect the stability and accuracy of calculations?"
Xiao Yi glanced at Xu Ming. It seemed that Xu Ming was also the original program expert of this research group.
Otherwise, I wouldn't have thought of this problem so quickly.
"Just combine it with adaptive mesh refinement," he replied.
"Adaptive grid..." Xu Ming thought for a moment and then clapped his hands, "Yes! I almost forgot about this technology! In this case, we only need to increase calculation points in high-precision areas and maintain coarser grids in other areas to optimize computing resources."
"Brother Xiao, do you think you have some understanding?"
Xiao Yi waved his hand and said with a smile, "It's all the same, it's all the same."
Luo Mingya asked at this time, "If this is the case, will we have to develop new code? Will it take more time?"
"This is no longer needed." Xiao Yi said, "Just make some modifications to the existing computing framework and integrate it. I suggest that we conduct a small-scale test first to verify the effectiveness."
"Well, let's do this. I'll give you an example now."
Next, Xiao Yi backed up the code first, and then began to modify the algorithm.
His actions immediately made several people present wide-eyed.
What kind of solid skills do you have to be able to make modifications on it with such confidence?
While revising, Xiao Yi also commented. "The calculation amount of first principles calculation feels a bit large. There seems to be a lot to calculate."
Luo Mingya nodded and explained, "Compared to Density Functional Theory, first-principles calculations have higher computer requirements and require greater calculation costs. That's why we are looking for your help. Anyway, we can't count on the old antique server in our college."