The top student must be diligent.

Chapter 139 You still say you know a little bit?
"The two-dimensional materials of the transition metal dichalcogenide family are well-known in our materials community due to the wide tunability of their electronic and optical properties."

In a conference room of the School of Materials Science and Engineering, Luo Mingya stood on the podium and wrote the three words TMD.

At this moment, she was introducing their topic to Xiao Yi in the audience.

Although Xiao Yi didn't understand, it didn't prevent him from being given some concepts in this way to help him understand the purpose of the course later.

Xu Ming and others also came and were sitting below 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 from Xu Ming and others how powerful Sun Lina was when she was young.

She is almost the same as Luo Mingya standing above. She entered the junior class at the age of 15, and then she completed her undergraduate studies in just three years, so she entered graduate school at the same age as Luo Mingya, 18. She completed her doctorate at MIT in four years, and studied abroad for almost eight years, and then suddenly returned to China.

According to the gossip provided by Xu Ming, she suffered a blow in her relationship, so she chose to return to China. Of course, she had already been selected as a Thousand Youths before returning to China, and after returning to China, she became an Outstanding Young Scholar. The various funds added up every year are consistently over 10 million.

She didn't give up completely. Occasionally, if there was a really good direction, she would take action. After returning to China, she had won a second prize in the National Natural Science Award and published two articles in top journals.

Basically, thanks to Sun Lina, the status of their laboratory is considered to be the best in their School of Materials, and even the laboratories of those academicians are not inferior.

But when she tanks, she really tanks.

Xiao Yi and the others all looked back and saw Professor Sun sitting at the back, holding her switch and wearing headphones while having a picnic.

Well, according to Luo Mingya's temper...

"Sun Lina! If you don't want to listen, don't come here."

As expected, Luo Mingya glared over immediately.

Sun Lina raised her head and glanced at Luo Mingya, then waved her hand and said, "Don't bother me. Even though I'm playing games, I can actually hear what you're talking about. Do you understand why you're trying to do two things at once?"

Luo Mingya: "Sooner or later I will have to complain to the dean about you, my horrible mentor."

Sun Lina: "It's okay. This year, about a dozen companies are planning to hold recruitment fairs at our school for my sake. There are domestic companies like Linde, Diaby, and Warwick, as well as a bunch of foreign companies. This year's spring recruitment will help our college relieve a lot of employment pressure, so the dean won't bother me."

Luo Mingya raised her eyebrows and said, "Very good. Since you have such a big face, it seems that I can go to Warwick and ask how the seven-digit servers are sold. Maybe they can give me a discount."

"Just buy it, there's so much funding..."

Sun Lina paused: "How many digits did you say?"

"Not much. Our budget is eight figures, so I'll buy one in seven figures."

"Stop, my little ancestor, please don't ask anymore."

Sun Lina finally put down the switch in her hand. "The annual funding for the laboratory is only a few thousand yuan, and you have squandered it all. How are we going to survive for the next 10 months?"

"Well, then listen to me honestly!"

Luo Mingya showed a victorious expression.

Sun Lina admitted defeat and sat down in the front seat obediently.

Luo Mingya continued: "So what's next..."

At this time Xiao Yi raised his hand.

"Does Junior Brother Xiao have any questions?" Luo Mingya said.

"Excuse me, what is this TMD?"

Xiao Yi looked at the three letters "TMD" she wrote on the blackboard and was very curious about what it meant.

Eliminate the most well-known answer first.

"Oh, you mean this." Luo Mingya smiled and said, "This is transition-metal dichalcogenide, abbreviated as TMD."

"I see."

Xiao Yi nodded, and everyone present smiled knowingly.

The unexpected coincidence made the atmosphere in the conference room a little more relaxed.

"Let me continue," Luo Mingya said, "In short, this flexibility in the physical properties of TMD materials can be traced back to their remarkable sensitivity to dimensionality, specific edge configurations, and stacking sequences."

"The most common polytype stacking sequence in TMD materials..."

"The phenomenon of polytypes, i.e., unconventional crystalline phases that display a mixture of stacking sequences, represents a powerful means to design and engineer new physical properties in 2D materials," said the team. "Inspired by this, the most important goal of our project was to achieve first-principles calculations of the optoelectronic properties associated with the 2H/3R polytypes in WS nanomaterials."

"That's the purpose of our project. I don't know if you've heard of the first principles that we'll use in the process. Like the density functional theory I mentioned before, it plays an important role in computational materials science."

"It is based on the Schrödinger equation in quantum mechanics to describe the behavior of atoms and electrons. It does not rely on experimental data and empirical parameters. The properties of materials can be predicted and calculated simply by solving the Schrödinger equation."

Xiao Yi listened to the other party's introduction, and his eyes lit up: "Does it also involve 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 material direction that spans multiple fields such as chemistry, physics, computer science, and mathematics. So no matter which discipline's methods are used, they can help us in our research."

"So you may also need to learn some knowledge about quantum physics next."
Xiao Yi waved his hand: "It's not a big problem."

One is learning, two is also learning, it’s nothing more than reading books.

He learned mathematics in the same way, so it doesn't matter.

Luo Mingya nodded and looked at Xiao Yi with great appreciation.

Compared to her junior fellow students, who couldn't even finish reading a paper, she didn't know how Sun Lina recruited them. The key point was that this woman didn't teach them, so in the end it would be her turn to teach them.

Tired.

Forget it. Comparing Xiao Yi with them, they are too unworthy.

If we really talk about the achievements in their respective fields, there is only a huge gap between her and Xiao Yi.

"Okay, these are the contents of our topic. We have now progressed to the state density and band structure analysis, and the current problem is mainly focused on how to use computational methods to simulate them to facilitate our research."

"I will send you the theoretical model we have finalized and our algorithm later. Hmm... you should be familiar with algorithms and programs."

Xiao Yi nodded and said modestly: "I know a little bit."

Xu Ming and the others next to them rolled their eyes.
Your mining software is valued by a mine owner with tens of thousands of mining machines. Can it be said that you only have a slight understanding of the algorithm program?
joke.

Luo Mingya nodded: "That's fine, Xu Ming, show the model and algorithm to Xiao Yi."

"Well...Xiao Xuedi, can you see if 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 started reading.

Although he didn't understand what the parameters meant, he quickly commented from a mathematical point of view: "The convergence speed and accuracy need to be improved."

"Well... the numerical solution method used can be improved first. I suggest considering using a more efficient iterative solver. Especially when dealing with large-scale matrices, introducing a multi-grid method is a good direction."

"Multi-grid?" Xu Ming's eyes lit up. "This idea is indeed feasible! The multi-grid method does perform very well when dealing with large-scale problems."

But soon he frowned and thought again: "But the question is, how can we ensure that these improvements will not affect the stability and accuracy of the calculation?"

Xiao Yi glanced at Xu Ming. It seemed that Xu Ming was also the original programming expert of this research group.

Otherwise, I wouldn't have thought of this problem so quickly.

He replied: "Combined with adaptive mesh refinement technology."

"Adaptive grid..." After thinking for a moment, Xu Ming clapped his hands and said, "Oh, right! I almost forgot about this technology! In this way, we only need to increase the calculation points in the high-precision area and keep a coarser grid in other areas to optimize the computing resources."

"Brother Xiao, you still say you know a little bit?"

Xiao Yi waved his hand and said with a smile: "It's all the same, all the same."

Luo Mingya then asked: "If this is the case, do we need to develop new code? Will it take more time?"

"This is not necessary." Xiao Yi said: "Just make some modifications to the existing computing framework and integrate it in. I suggest that we conduct a small-scale test first to verify the effectiveness."

"Well, let me give you an example now."

Next, Xiao Yi backed up the code, and then began to modify the algorithm.

His action immediately made the eyes of several people present widen.
What a solid foundation one must have to be able to make changes on it with such confidence?
While making the revisions, Xiao Yi also commented: "The amount of calculation for the first principles calculation seems a bit large. There seem to be a lot of things to calculate."

Luo Mingya nodded and explained, "Compared to density functional theory, first-principles calculations have higher requirements on computers and require greater computational costs, so we are looking for your help. Anyway, we can't rely on the old antique server in our college."

(End of this chapter)